I like how they don't understand the criticism isn't actually of a small penis, as the quoted guy notes it's of the behavior being seen as compensation.
It's hilarious and annoying because the guy is right - they're attributing a set of behaviours to a physical attribute, something you'll get banned for if it was about anything else. But it's something they do, and he's calmly pointing it out, so their cognitive dissonance kicks in.
I remember seeing this effect on a forum where the topic of men being raped by women came up via a study showing that it's far closer to parity than the 'men are rapists, women are victims' mentality which most people, but especially leftists, have. This wasn't men being raped by men, it's how men don't say or think they've been raped, but if you ask if things that constitute rape have happened to them, many many more of them will say it has. And it was hilarious because you could see how their views on feminism and empowerment were theoretically, 'a sexually liberated woman can want sex as much as men and shouldn't be judged for it,' but were all built on the preconception of, 'men always want sex and would never turn it down, therefore they're the only sex that can truly be predatory because women never actually want sex so badly they'd coerce a man into it.' So their reactions were them visibly trying to work through their own logical contradiction, with different posters having differing levels of success.
And the thing is, ResetEra isn't even at a point where you can see the users struggling with their own doublethink. To them, this small dick post, like a post about women raping men (and not even 'women'), should flag something in their brain - but it won't. Because they lack the introspection or desire to be logical. So making fun of someone for their innate attributes? World's worst thing if it's that they 'were born in the wrong body', or are black. But they're a man who's smaller than average - and I believe they've had a thread before about actual height, not just dick size? Nah, that's fine, because I do that, and I'm not wrong.