Let's compare it to the Miller Movement. 1843 and 1844 came and went without Christ's return. One response is to admit the mistake. Storrs, a leader in the movement, rejected the date, that the movement was led by God, and rejected date-setting. This is the most painful response, but is the healthiest in the long run. Another response is "the wrong event at the right time". This is the SDA approach - the investigative judgment. Another response would be to set new dates. This is what the Second Adventists did.
The Bible Students/JWs have used these responses also.
The Watchtower would not have self-destructed if 1914 came and went peacefully, because it was not like the Miller Movement, which was based alone on the date-setting of 1843/1844. There was not enough to hold them together through the disappointment. The early Bible Students had other beliefs that set them apart from others, and were reasons why people joined Russell's group, such as hell, Arianism, restitution, the Kingdom, the two salvations, and there were ones that were likely attracted by Russell himself. These beliefs would have sustained the group, although many could have left.
Russell's changing expectations about 1914 is complex and not easy to explain. Russell expected that the time of trouble would occur between 1874-1914. There would be the three phases based on Elijah's experiences: War (wind), Revolution (earthquake), and Anarchy (fire). By 1904, Russell expected that the anarchy phase would occur between 1914-1915. But as 1914 approached there was less time for his predictions to come to pass. When the World War started in 1914, Russell saw this as the fulfillment of the first phase of War, which would be followed by worldwide revolution and then anarchy. It was apparent that other predictions had not been fulfilled, so the Bible Students were in a state of confusion, but looked to 1915, 1916, and 1918. Russell died in 1916. After the World War ended, the Russian Revolution occurred, which appeared like the Revolution phase had begun, and that the communists were taking over, as Russell had predicted.
From the vantage point of 2006, it is clear that Russell's chronological system failed, but it was not clear at the time. If nothing had happened in 1914, and Russell had rejected the whole system, the Bible Students/JWs would have been in the long run much heatlhier, although the disappointment and pain would have been greater. But the world events and Russell's death left the BIble Students confused over the predictions and vulnerable, and they never fully recovered. In the aftermath were divisions over Russell's predictions, Rutherford's manipulations, the Finished Mystery, the glorification of Russell, etc.