In my view, schools ought to allow students to express various points of view as long as it's not hostile. I don't think, in my view, the T-shirts don't rise to the level of creating a hostile environment. I do think that some things go overboard.
The broader issue is there are many U.S. conservative Christians who feel that public schools have become hostile to their faith.
Americans are deeply divided over homosexuality in our society. But if school officials and community members use the ground rules of the First Amendment, they can reach agreement on how public schools can guard the rights of all students in a safe learning environment.
Generally speaking, private and religious schools are not subject to the First Amendment.