James Gunn used to be an edgelord fuckboy. When he got Guardians, his past bubbled back up, and he responded by accepting responsibility, admitting fault, and promising his actions would show he'd changed.
There was another time he was kicked off a film because of that same past, and his response was basically, "Yeah, it sucks I'm off the movie, but I did do and say those things, and sometimes you have to take responsibility even after you've changed."
I cannot stress enough that he has never tried to justify his past actions or make excuses (and his edgelord persona was about talking about which video game characters had the biggest tits and saying the grossest things he could in a period where it was seen as a badge of honor to get people to yell at you).
Anyway, glad to see he's using that old edgelord energy to piss off people to talk about the movie more. Because he's not a dumb guy. He knew calling Supes an immigrant (he's right, fyi) would make the loudest assholes in any room get loud and put some attention on the flim.