My problem with All-Stars is that it was so cartoony and arcadey that it became it's selling point and it felt too gimmicky.
The SD! games were just natural video games that existed in a time where the scope of these "realistic" games just wasn't possible due to limited animation and the like. And also when WWE itself was more edgy and in some ways, video gamey. The games just captured the tone of what WWE was at the time. But that's changed ever since '09-ish.
With that said, I also prefer the SD! games of old. The new games do have quite a few things to like, though.
Gamecube is still one of the best consoles ever, so many great games. ---