Wow, okay, I didn't know there was so much spite coming from those places. And here I thought artists were the ones who were doing most of the yelling. Geez, at least I've never seen an artist who clearly just wants to 'make the techbros mad'
Not towards artists in particular, but I do feel like IP in general* is kind of elitist. A common argument I hear against IP abolitionists is 'if I invent something that saves millions of lives, I should never have to worry about money again. If I don't get to own my invention and continuously profit off of it, I might as well do a boring normie job if it pays the same amount'.
The idea that creatives and intellectuals (heck, this includes AI inventors) deserve to 'own' their work instead of being compensated for their time like everyone else feels very 'we are geniuses, we are better than those normies who can only do normie stuff, our time is worth more than theirs as evidenced by the continuous good impacts our work has on the world, therefore we should be compensated for said continuous good impacts. Exchanging our time for money at a fixed rate is beneath us.' (Don't forget any of those 'normies' could one day create or invent something spectacular as well, and are probably not already doing so because all their time is currently spent on doing their 'boring normie work' in order to keep afloat)
(Again, this is not aimed at artists in particular; e.g. commission artists do get paid for their labour instead of extracting rent from their ideas, which is the opposite of elitist :] And I'm also not saying that anyone reading this who supports IP consciously thinks this way :'D)
In that sense, I do in fact see violations of IP as 'taking back intellectual creation from “the Man” and give it to “the people”.', and that's why I had an initial knee-jerk sympathy towards AI art partially because of the art theft complaints. But I have to admit the pro-AI people are being incredibly hypocritical; it doesn't seem like they want to free all information for "the people"; it seems like they just want to become "the Man" themselves.
I say this as someone who does both art and math, and is not in any of the 3 categories you listed 
*
Heck, private property as a whole, in fact. If anyone reading this is a socialist, surely what I wrote above pertaining to IP rings a bell concerning a certain other kind of property?