My counter:
Not all people object to homosexuality because they want to treat others less than human or be racist. (Sure, some do, but that issue will never be eradicated because the problem with humans is that we're human.) I believe most reasons that people object homosexuality with are moral / religious reasons. This applies to school, too. People might want to expose their kids to homosexuality in their own way (the classic "talk") for the reason of raising their kid their way, religious or not. Every family is different, so it might be best to keep sexual topics out of school and let parents deal with them, the way their kids need to see it. I feel this is a valid concern, to want to raise your kids your way, and I do not see how in any way that doing so is racist.
