I recall that Claremont wrote in Avengers Annual #10 that he possessed the emotional maturity of a child and did what he did as a means to escape from limbo to Earth, so Claremont definitely didn’t mean to write that off as heroic, and that if Shooter had been more responsible and didn’t fail to maintain his duties as co-writer, I think that Shooter would have characterized the Avengers more as negatively responding back to Marcus as a villain, as opposed to being more ignorantly passive about it.