From the way I understand it, individual, student prayer is not forbidden -- teacher/faculty led prayer is, because it coerces the students into a particular faith. To allow faculty-led prayer would be intimidating to students not of the particular faith of the faculty member, exploit the vulnarability of the child for sectarian purposes, and moreover, it would dilute the meaning of true faith.
This is why I don't understand the pull of forced conversions. It dilutes the faith. People should come voluntarily and of their own free will into any philosophical ideology, and to compel someone into a system of belief by force, authority, or other means aside from the desirability of the ideology itself, is to show a LACK of faith in the basic value of the base philosophy on the part of the person doing the proselytizing.
That being said, there are still parts of the United States where teachers are more than willing to break the law on the separation of church and state, and dictate their religious views as though they were approved of by all. When my daughter was in high school 9 years ago, her Algebra teacher called me because she was concerned that my daughter had expressed she was a nonbeliever when the teacher was using her religion as a tool to intimidate submission into the class ("if y'all don't behave proper, yer goin' ta hell.") -- when I informed this teacher that I was completely aware of my daughter's infidelity, and I, myself, did not believe, she had the gall to insult me by saying "Ya mean y'all are satanist, I mean atheists?" It took three different incidents with calls to the principal, finally threatening a law suit, to get this woman to back off.
WOM - if you had a child in public school, and their teacher was a Muslim, who used these sort of strong-arm tactics to bring the class into submission to Allah, how would you feel? Would you think the public school would be a place for this sort of prostylizing to take place? What if the teacher were a Scientologist? Would it be proper for that teacher to suggest the children be scanned for Engrams?
The reason "No word of God must reach this crowd" is because the jury is still out on the authenticity of a supreme deity and just who/what He/She/It is. If one deity is allowed in and supplications made in their name, then ALL of them must be allowed in -- which then is an affront to "the one" that insists all the rest are "idols and false gods."
If you cherish your faith, then you'll keep your faith in the private sector, where it won't get blasphemed, trashed, polluted, and desecrated by the infidel.