DBZ fanboys are furious
I can sort of see why they had Supes win again. It's basically because comic book writers are inconsistent and don't put any sort of cap on his powers, so you have comics with him doing shyt that shouldn't even be physically possible, like holding a black hole or lifting something infinitely heavy. Goku just can't compete with that.
Animated Superman is neither here nor there, pretty much any animated version of Superman (especially the DCAU one) is toned way down from the comics, so him being beaten by someone doesn't really prove anything.