Exactly, Superman didn't need that, hes already there.
Also, Superman has a Superhuman thought process. Wasn't Goku an alien Jeff Spicoli?
I'm just curious, I have probably seen one of the movies and a handful of episodes, and it was generally just when they were fighting someone I thought looked cool, but I never saw Goku do anything that I thought would put him in Superman's category.
You have to remember most writers have to dumb Superman waaaay down just to have a competitive storyline. You take Superman with his powers as described or something like Superman Prime, its just hard to imagine him being put down.