A lot of it is contextual.

Sometimes, it’s based on larger patterns of subtle behaviors that wouldn’t be indicative of a problem on their own.

Sometimes, people are doing harmful things by accident because they grew up in a culture where those shitty things are normalized.

Sometimes, people are doing things which would not be harmful on their own, but are associated with negative experiences that are only common for the minority group.

Sometimes, people who have a long history of being timid have gotten fed up with putting themselves down for others’ comfort, so their pendulum swings the other way and we only see the tail end of that.

And yeah, sometimes it’s someone who’s immature or aggressive for unrelated reasons and isn’t thinking super hard about what they’re doing beyond finding a weakness and attacking it. Social media design makes this worse. I think situations where that’s all it is are less common than we think, though.

There’s also often ingroup/outgroup dynamics at play. And what makes it worse is that people who exist outside of the grey area of acceptable behavior, people who are just genuinely cruel, will do something cruel and then retreat and act like they belong in the grey area. They learn the ways that they act when people are genuinely uninformed or confused or curious and they copy them, all the while refusing to back down from the shitty thing they did. It’s kind of a charade put on for onlookers to make the victim look like the aggressor.

For the specific issue you mentioned, the good faith interpretation is that, yes, boys can wear dresses. If that’s the end of it, that’s fine. But “wearing a dress doesn’t make you a girl” is also a common phrase used both by malicious transphobes and by misguided loved ones trying to talk their kids out of being trans. There are many reasons that discussions like these are so hard to get the phrasing’s right on is that we don’t have established social norms to make them easy. The established social norms, in fact, make them actively more difficult. And people are doing gender exploration in a matter of months that would have been spread out over years of their childhood if they’d been allowed to do so. It’s just a lot.

I genuinely hear your frustration. I hope you hear mine. Learning all of this has been a painful process and I hope we can see it get easier in the near future.