Thing that DC found is that the (mainstream) comics they put out afterward alienated everyone but their oldest fans, who LIKED all that confusing history.

Mainstream fans like that stuff. Otherwise Marvel would no longer exist, as if you recall they've never thrown out said history, and theirs is a lot more twisty and vast, whereas what was confusing about DC is that often they ignored it. They were trying to be more like Marvel in adhering to only one.