Actually my answer was cut short due to a technical problem I had on this end, so let me start again.
The Scriptures are filled with examples of approved public prayers, such as the prayer of Hannah (1 Samuel 1.9-28), the prayer of King Solomon at the dedication of the First Temple (1 Kings 8.22-61), and Ezra's dramatic display of prayerful contrition that moves the entire nation of Jews to repentance (Ezra 10.1-4). And it doesn't end there.
And let's not forget, the biggest book in the canon is the Book of Psalms, a collection of public prayers used by Jews and Catholics as such to this day.
Though as most of you know I am not a Christian, so I don't believe in the inspiration of the New Testament, Christians claim that the following texts are inspired of the Holy Spirit...and they include public prayers.
The Magnificat or Canticle of the Virgin Mary--Luke 1.46-45.
The Nunc Dimittis or Song of Simeon.--Luke 2.29-32.
Each time Jesus miraculously fed the crowds.--Matthew 14.19; Mark 6.41; Luke 9.16; John 6.11.
The public prayer of Jesus that was answered from heaven.--John 12.28.
So comparing the Scripture of Jesus from Matthew 6, and not forgetting the above texts from the Old Testament, is it being intellectually honest to say Jesus is contradicting the rest of the Scriptures or that Jesus is condemning public prayer?
Note the context:
"Be careful that you don’t practice your religion in front of people to draw their attention. If you do, you will have no reward from your Father who is in heaven.
Whenever you give to the poor, don’t blow your trumpet as the hypocrites do in the synagogues and in the streets so that they may get praise from people. I assure you, that’s the only reward they’ll get. But when you give to the poor, don’t let your left hand know what your right hand is doing so that you may give to the poor in secret. Your Father who sees what you do in secret will reward you.
When you pray, don’t be like hypocrites. They love to pray standing in the synagogues and on the street corners so that people will see them. I assure you, that’s the only reward they’ll get. But when you pray, go to your room, shut the door, and pray to your Father who is present in that secret place. Your Father who sees what you do in secret will reward you."--Matthew 6.1-6, Common English Bible, italics added.
If you notice Jesus is not condemning public prayer any more than he is condemning giving to the poor. What Jesus says is not to pray or give to the poor "like hypocrites." Hypocrites do so "in front of people to draw their attention" and to "get praise from people." If that is why people do things, Jesus said that is the reward they would get--and nothing more! But it isn't a condemnation of public prayers.
However, I do want to add that there is nothing in the Bible that says that Scriptures cannot contradict one another. Guess what? That was invented by the JWs and other Fundamentalist Christians. Because the Bible was never intended to be an exhaustive compendium of theology and religious doctrine, each of the books was written for different purposes. You will therefore find many contradictions within.
This creates a paradox for some Christians who attempt to excuse them away with complicated and illogical arguments. Yet this is not one of those cases. Public prayer is a staple of both Judaism and Christianity, especially since they are liturgically based religions. True, most JWs and even some exJWs have no idea what liturgy is and its importance to the history of both these religions and the shaping of the Scriptures themselves, but a simple review of the subject via the Internet should suffice to show that one of the main reasons Scriptures were collected was to use as public prayer texts.