I think the point is that reasonable compromises tend not to be sufficient for trans rights activists - for instance gender-neutral toilets are not acceptable because transwomen, being women, demand to use the women's toilets. It's all or nothing.
I think the reference to Reddit was because it has banned gender-critical contributors, and therefore it is a platform famous for very extreme and uncompromising 'trans women are women full stop' arguments, along with violent and threatening comments about gender critical people.
Even very reasonable and compromising comments, like JKR's 'dress however you please..' tweet, are attacked on Reddit, so 'try that on Reddit' usually means 'It might seem reasonable to us, but Reddit will shred it!'
It's not usually intended literally, I believe.