https://steamcommunity.com/discussions/forum/0/595140258825272625/
the "this thread has devolved into non-productive discussion" thread lock reason always feels disingenuous because usually it's on a thread like this where it was started as a trolling attempt, succeeded at that, has 170 pages of replies, and the last few pages of replies are very civil (in this case, it's just people explaining that transgender video game characters are as old of a concept as video game characters)
serious answer
@ben Because the "devolved into non-productive discussion" usually doesn't mean "there is bigotry", it means "there is overt conflict", which is a different way to view "someone called out the bigotry".
It's not a coincidence that this so often happens (in many places, not just on Steam) *just* after people start pushing back on the bigotry. It's what you get when a place is moderated by people who care more about avoiding conflict than they do about creating a safe and inclusive environment.