There are several fundamental flaws in the essay. Below is a list of the most obvious problems.
Firstly the article admits its bias. It frequently uses the pejorative term "apostates" (ignoring the true meaning of the word), and dishonestly states that all "apostates" are trying to make people leave the "truth" rather than genuinely believing the Witnesses' beliefs are in error.
Early on, it is suggested that secular evidence is "anti-biblical", implying that the bible cannot at all be reconciled with the secular evidence, which is not true.
The actual meaning of "chorbah" is ignored. The actual meaning refers to a place which is becoming desolated, though the article implies that it can only refer to complete destruction that has already occurred. (Significantly, Daniel's specific wording of "fulfilling of the devastations", indicates that Jerusalem would be 'completely' devastated by the end of the period, not necessarily for its entirety.)
The article ignores the fact that Jeremiah clearly stated that "nations" would serve Babylon for seventy years, not that Jerusalem would serve for 70 and other nations would serve for a shorter period.
It falsely suggests that the taking of Daniel and other youths must have been an 'exile', though it only meant that captives were taken as booty to prevent a siege against Jerusalem by Nebuchadnezzar on his return to Babylon before he ascended the throne. It falsely alleges that for that to happen, Jerusalem must have been 'conquered' at the time, whereas it actually saved it from being conquered. There are indeed secular records that "booty" was taken at the time, and booty usually included captives.
It distorts the timing of Jehoiakim's 4th year, ignoring the fact that Jeremiah's reference to Jehoiakim's 4th year is actually the same as Daniel's reference to his 3rd year (using the accession-year system); instead it suggests that Jeremiah was referring to a year later. It also builds upon the false premise of an 'exile' at that time, by suggesting that events of Jehoiakim's 5th year are incompatible, though none of the named youths taken to Babylon are named as being in Jerusalem in that 5th year. (Indeed, that Nebuchadnezzar stopped the siege after being given booty would have made it likely to assume that the Babylonians might not attack again.)
It incorrectly links the "calamity" mentioned at Jeremiah 25:6-7,25 with the beginning of the 70 years, and erroneously assumes that Nebuchadnezzar coming against Jerusalem must be synonymous with nations serving "the king of Babylon." Additionally, it ignores the fact that Nebuchadnezzar could validly be called 'king' in the same fashion that Belshazzar was called 'king', though he was really only prince.
It presents a 'strawman' argument about cities in Judah still having inhabitants to somehow suggest that there could not have been any previous exile of captives taken prior to the destruction of Jerusalem.
It quotes part of 2 Chronicles 36 starting from verse 19 to allege that the destruction of the temple is indicated to be the beginning of the 70 years, ignoring the complete description of what actually happened at Jerusalem over a number of years culminating in its destruction and reducing the supposed explanation to only the destruction of the temple.
It ignores that Jeremiah 25:12 explicitly indicates that Babylon's king would be judged only once the 70 years had ended, and that Daniel indicates the numbering of Babylon's days and its calling to account at Daniel 5:26-31. (In so doing, it also ignores that the Bible places the beginning of the 70 years [relative to the known date of 539] in 609.) Instead it illogically suggests that the nations were still in slavery to Cyrus for two more years, contradicting the order of events at Jeremiah 25:12.
The article attempts to confuse the reader about Jehoiakim's 3rd year actually being his 3rd year (or 4th including accession year), and asserts that baseless "vassalship" theory of the Society.
It quotes Jeremiah 28:14, falsely alleging that the 70 years had not yet begun at that point, ignoring the beginning of the chapter which indicates that Jeremiah was repeating the prophecy in reply to Henaniah's suggestion that the already-current yoke of Babylon would be removed in two more years.
It suggests that the 70 years began when Jerusalem's king was removed though it had previously been ruled by an Egyptian-appointed king.
It ignores the accession-year of Nebuchadnezzar to try to introduce confusion between Daniel being in Babylon for 3 years before meeting Nebuchadnezzar and interpreting Nebuchadnezzar's dream in his 2nd regnal year. (Since Daniel was taken prior to Nebuchadnezzar's accession to the throne, it allows for 3 full years plus some months to elapse and still meet Nebuchadnezzar during his 2nd regnal year.) The article uses its false reasoning to further allege that Nebuchadnezzar's reign is relative to vassalship of Judah.
It specifically ignores the application of the 70 years of servitude for Tyre, suggesting that it will simply be "forgotten" in a sense of trade. It quotes Ezekiel 26:1-4, but intentionally omits verse 5 and 6 which indicates that it was not to be simply "forgotten" in the sense given in the article. Additionally, it gives an interpretation for Tyre being "hired" without basis. Further, the article contradicts the application of the 70 years for Tyre given by the Society in its Isaiah's Prophecy publication (volume 1, page 253).
It misapplies the degree of destruction of Egypt during the "forty years", assumes a starting point that is not the only possible event to start from, and falsely alleges that a period of Babylonian desolation of Egypt fits only their interpretation. The article contradicts the Society, which states that the forty years "began with Egypt’s decisive defeat at Carchemish on the Euphrates River by the Babylonians under Nebuchadnezzar in the early part of 625 B.C.E" (actually 605BC).
The article ignores the fact that Zechariah refers to a period of 70 years that had not yet ended, and that makes no sense, neither logically nor textually, if referring to a period that was not still current. It distorts the sense of the question "how long?" away from a question of frustration with circumstances (as used in almost every instance of the form of question throughout the Hebrew scriptures) to suggest that it refers to a period of unknown length beyond the 70 years.
The article accepts the date of 539 for Babylon's fall though it is derived using the same means that it rejects for dating other events.
It gives a redundant 'strawman' refutation for Babylon being destroyed in 519, which is not alleged at all by any source. Beyond listing meaningless dates that this might mean for the Messiah, it indicates a shifting forward of the date for Rome's fall without any scriptural reason at all.
It alleges that it has exact dates for beginning its 70 years, though the dating of 537 for the return of the Jews is speculative, and contradicts Josephus' statement that the temple rebuilding began in Darius' 2nd year, not his 3rd.
It falsely states that Thiele contradicted himself in stating "not pretend to give a complete list of all the rulers of either Babylon or Persia" and "It is accurate and reliable all along the line", though the latter comment simply indicates that what is stated is correct though not that it is necessarily "complete"
It attempts to cast doubt on extant contemporary Babylonian evidence, though offers absolutely no alternative Neo-Babylonian chronology based on any of the supposedly anomalous tablets.
The article suggests that Josephus agrees with the Society for their interpretation of the seventy years, though Josephus indicates a specific period of 182.5 years between the end of the 10-tribe kingdom and the reign of Cyrus which is not compatible with their 70 year interpretation.
The article falsely alleges that no other views allow for exactly 70 years.
The article provides a baseless and untenable explanation for why Ezekiel 33 indicates that there were still inhabitants in Judah after the 12th year of exile. (The fact that the "devastated places" can have "inhabitants" at all indicates that the Society's view is incorrect.)
The article states that Jeremiah 29:10 was not directed to "the first batch of exiles", however Jeremiah was writing from Jerusalem, and the "first batch" was the only 'batch' of exiles in Babylon at the time. It would be meaningless to tell them about a 70-year period that hadn't started yet. The argument also ignores that almost all translations properly translate the verse in harmony with the initial definition of the 70 years given at Jeremiah 25:11-12.
The charts for the 70 years seek to indicate all non-Witness views as invalid, and do not indicate the exact 70-year period running from 609 to 539, consistent with secular history, as well as Jeremiah 25:11-12 and Daniel 5:26-31, which the Society's model contradicts.
One of the charts in support of the Society states: "The land "in ruins" and "without an inhabitant" for exactly 70 years", though the bible does not say anywhere that the Judea would be "without an inhabitant" for the entire 70 years.
In summary, the article is dishonest, biased, incomplete and flawed.