While I think that it is odd to ban the discussion of anything in school, I would also think that the discussion of homosexuality outside of dedicated sexual education courses (when children are under a certain age) has far more to do with political indoctrination than it does with education; and I suspect that this is why so many people are upset about the ruling.
Regardless of whether you agree with it or not, the reason why homosexuality (and many other topics) is being taught in school today when they weren't when I was a child is because activists want to counter what they would call "misinformation" that these children are receiving at home. This is not the schools job and, being that they do such a piss-poor job of teaching children the fundamentals today, spending any resources towards these activities is wasteful and a poor use of time.
