You notice how anyone who is male tries so hard to make themselves look as threatening, and intimidating as possible?
Are we just talking about basic gender behaviour here?
Discuss.
Probably because we're biological creatures and the male sex has testosterone, the hormone that makes us.. well.. aggressive, competitive and intimidating. Now clearly, the people you've met must not have a lot of emotional intelligence to keep their chemicals in check.
NOTE: They're probably not trying hard at all, it's more difficult to keep them in check than to not.
I'd also like to add that on the internet where there is more or less complete anonymity, there is no shame in expressing oneself, especially on the lesser moderated platforms, where Free speech truly reigns.
I suggest you take things with a grain of salt and realise you can also scratch back, on those places that allow it.