In general I try not to be hateful, but have you seen this guy? He’s awful in every conceivable way short of kicking puppies! This is an exaggeration, but when I think about him I get so angry that I need to make a blog post about it. [Disclaimer: I’m doing this mostly from memory, so I may get a few facts wrong. Feel free to correct me.]
-The first time the reader is introduced to him, it is as a lazy, pretentious hypocrite; he would rather lie at home contemplating the universe than work to feed himself. As a result of this, he has to take charity from Courfeyrac by living in his house and borrowing large amounts of money. He hardly talks to Courfeyrac, does not try to fit in with Courfeyrac’s friends, and takes him for granted.
-While Éponine lies dying on his lap, he does not even have the decency to try to remember her name, despite the fact that she has saved his life several times.
-While he is first falling in love with Cosette, he stalks her and her father, which, while creepy, is a fairly standard romantic trope. However, after they are married, he treats her like a child. He intentionally manipulates her into forgetting and ignoring her father—paying attention, in short, only to him. He takes away her agency (and goodness knows, as a woman Cosette has already suffered enough of this) and treats her as a prize. This may also have been acceptable during the time when it was written, but I think that, even for some back then, forcing one’s wife to neglect her father might have crossed a line.
-Marius’ attitude toward Valjean is excused or rationalized with his not having known that Valjean saved his life. He believed Valjean to be a dangerous criminal, but this really is not a good excuse for what he does. Essentially, Marius systematically destroys Valjean’s reason for living in hopes of causing him to die. That is supervillain-level manipulation of his wife and father-in-law right there.
In conclusion: Marius abandons his ideals for the first pretty girl he falls in love with, stomps on other people in his single-minded quest to obtain her, and then tries to ruin her life after they get married. And he is not presented as one of the many characters in need of redemption, probably because he did it for true love.