Because you've been lied to. You've been duped by hate groups, and now you're happily spreading their disinfo.

> Also: is there any indication that this is (in the sense that people need transition or otherwise kill themselves) is a problem in other societies than ours (or just with a bunch of apes). Because I still think that we should maybe change our society before we do hardly reversible things to people to make them fit in (very unpopular and quite influenced by conservative christianity (though I'm not affiliated))

It's not a problem in other cultures because other cultures just let people transition. Without transition we do see increased rates of distress, including higher rates of attempted suicide and deaths by suicide.