Legally they did nothing wrong, but ethically they were pieces of shit and were stealing something that didn't belong to them because their company just coincidentally was called Marvel Comics. Its one of the most blatantly shitty moves one of the Big 2 companies has done to the other.
She's no more captain Marvel then Justin Bieber is Captain marvel, and I'm not the foolish one.
As opposed to people like you, who want to erase history? If you don't give a shit about the character, stop posting about it. I don't go into threads about, I don't know, My Little Pony or Supernatural and just start randomly shitting in them. They're not things I care about, so I don't post about them. As opposed to the real Captain Marvel, who is my favorite DC superhero.
DC is ran by people who explicitly hate comics, which is why we get shit like this. Hell, current DC Editor in Chief Bob Harras has a history of literally disliking a character named Captain marvel, although ironically it was the third marvel version (Genis-Vell). The whole thing involved a stupid comic pissing contest where Harras thought he could write a book to outsell Peter david's Captain marvel book (Bob Harras's book was really fucking shit and Peter David's book kicked its ass in sales).
That said, if the movie called him Shazam but still used the real character? I'd deal with it. But, they're not using the real character with a name change. They're using the anti-social shithead original character that geoff Johns created and then named Shazam so that DC would publish the book. So, really, the name is pretty damn low on the list of fuck ups, especially since no one forced Warner Bros to use Geoff Johns shitty punk character (who, to be fair, never fortnite danced or did other modern idiot bullshit so WB somehow made their Shazam worse then Geoff Johns version). You can't even say that was to appeal to teens, because I didn't see Tom Holland dabbing or doing other shithead things yet Spider-Man is still popular.