I think more than anything I see Ellis as adding subversive elements with regard to superheroes.
Well, his original superhero works are pretty damned subversive, that's true. His Marvel work always struck me as fairly tame, though. I think the most subversive thing he ever managed at Marvel was Nextwave, which sold rather poorly and only seems to have substantially affected a few characters (mainly Machine Man).
Anyway, I don't think adding subversive elements to superheroes is necessarily inappropriate. Superman when launched was an extremely subversive character, that's why he got popular. Most Golden Age superheroes who achieved any real measure of success had a subversive element or two to their backstory.
The idea that superheroes should be defenders of the status quo got introduced in the 50s, during the genre's first mass die-off. Only the blander books that parents wouldn't hate could survive. When superheroes came back in the 60s at publishers other than DC, they were written very cautiously until the genre was solidly re-established in the 70s. Then in the 70s guys like Ghost Rider and The Punisher start showing up.
My problem is that a lot of writers won't write straight superheroes anymore since they are too "boring" and while I personally don't like that view in Ellis's case I can at least respect him for not trying to hide it.
I think the villain there is genre saturation more than anything else. If you look at the kids' lines Marvel and DC have put out over the years, a lot of really fantastic straight superhero stories were published there that sell in very poor numbers.
Then when those creators got promoted to the big leagues, they... immediately had to stop writing straight superhero stuff, because if they did their work just wouldn't stand out very much. There are just too many superhero books for plain Jane genre material to find a market.
Honestly I have no idea what Millar actually likes, he clearly doesn't like superheroes otherwise he wouldn't have spent this last decade writing what he has.
Millar is apparently a
huge superhero fan with pretty nuanced views on the genre. He's just one of those fans-turned-writer who learned the hard way that if you do polished genre work, you'll never sell books. Millar's career didn't take off until he started writing the hyperviolent schlock stuff he's now known for. I think now he just keeps doing it because it sells. If it ever stopped selling, he'd do something else.
The humanity that helped define them has been tossed by the wayside to allow for events to happen, and it just isn't Millar.
The idea of heroes as necessarily infinitely compassionate is another trope that worked its way into the genre in the 50s. If you go back to the 40s, some heroes were nice guys and some were just goddamn terrifying.
Early Superman could and did threaten people and The Specter was, well, the Specter. Most post-50s heroes were basically nice guys if they were created in the 60s and then started getting weird again when the 70s rolled around.
I think the real problem with a lot of modern superhero writing is that it tends to rely on characters doing things that are shocking and uncharacteristic. Then instead of offering a good explanation for why the character did that to begin with, it's left unexplained and then later retconned or swept under the rug when it's time to move on to the next plot.
The real problem as I see it is that the publishers have decided that only actionactionaction and plotplotplot sell books. This leaves little room for characterization or theme, which are the story elements that tend to hold on to the longer-term fans.
Or the fact that writers have been constantly referencing Hank Pym hitting Janet/Wasp yet no longer even mentioning the events surrounding it.
That's because most fans who are aware of that little factoid about the characters have never read the book it happened in, and don't want to since it's old and not reputed to be an especially good comic. So kind of like Tony's drinking problem from Demon in a Bottle, it gets exaggerated into over time by fans who've never read the original material, but want to repeat the fandom's "in-jokes." So after awhile one of the first things people learn about Tony Stark is that he has or used to have a drinking problem.