Fair enough, but Sin is still Sin. The presence of allegedly worse Sins, doesn't make any one Sin into something moral and good.
There may be worse forms of Theft; but, in principle -- arguing whether or not we want to have sponsored Prayer in Public Schools, is like arguing about whether or not we want to have sponsored Prayer in Abortion Clinics.
There shouldn't be sponsored Prayer in Public Schools, or Abortion Clinics. Both are FOUNDED upon Violations of the Ten Commandments (the 8th and 6th Commandments, respectively). Both are Satanic and both should be abolished, not "sanctified".
All sin is an offense and disobedience against God. There is no such thing as a "good sin." However, each sin has a greater or lesser "offense value." If I steal a quarter from you, it doesn't have the same "offense value" as the sin of abortion.
Public schools in and of themselves are in no way, shape or form the moral equivalents of abortuaries.
How about the internet? One can't say that the internet is satanic because it can give access to satanic things. There are also good and even holy things to be accessed on the net.
In other words, there are things that are intrinsically evil, e.g., satanic or pornographic websites and abortuaries, and things that can be used for good or misused for bad, e.g., the internet or public schools.