While I do very much understand your point, I heavily disagree due to one point
One of the biggest reasons of teaching history is to make the future generations learn from past mistakes and to avoid them as much as possible. If we do not teach kids about the horrors people did, and still do, to queer people and other minorities, then these mistakes might be repeated again.
However, anything else related to LGBTQ in school (besides s*x-ed) that's not history related does not really belong there, so I do understand your point. I just think that teaching history to avoid it being repeated is very important