It's really weird to see such a near perfect design get hated on...
I love Kuu's look. Makes sense lore wise. It's even explained right before he's born, hehe. He doesn't just look it, but actually IS the fusion of Kid Buu and a Saibaman. He must of got his plump lips of Supreme Kai's sister's spit, hehehe!
I thought Fat Buu looked really stupid when I first seen him, but he quickly got love. I toned down and accepted it when we got into on how his look changed from absorbing the fat Supreme Kai. Lore is a pretty big factor for me on accepting "bad" designs. Otherwise, I wouldn't like One Piece at all, hehe. We're also buddies now, so I'd rather not hurt his feelings. If any of y'all ever figure out how to handle your multiverse stuff, just don't let him know I was disappointed in him for gaining back all that weight he lost training for the 1st Tournament of Power...
Anyway, I guarantee about 5 to 10 years from now, Kuu's design will be loved too.