>>100852044Main reason is actually because how DC was trying to SELL Superman in advertising, on covers, etc.
You have Superman always with red eyes, striking an aggressive pose, wearing this dumb armor.
It was all meant to tell people "this ain't your daddy's Superman! Superman's BADASS now!" and that rubbed people the wrong way.
In the actual stories he wasn't really written out of character, but at least half the time he lacked that clout he used to have of being the Bruce Springsteen of superheroes, the guy everyone looked up to and who's been around forever.
Even when he was written like Superman, that lack of history added to the feeling that this wasn't what people wanted from the character.