The difference is that Cloud has the most polarizing doubles win condition in the game. No other single character has something that gamechanging. Certainly not the fatties. You get all his ridiculously good handoff throws, amazing edgeguarding potential, great lasting hitboxes FOR handoffs, a virtually godlike kill move Smash attack for handoffs, excellent 2v1 potential, great ledgetrapping.....and Limit on top of it. Fatties just have the handoffs and a bunch of extra negatives.
Double Uair Up B isn't at all long considering the teammate will most likely be fighting someone else. Even Bayo stuff is pretty short. There's the extra issue a lot of characters have of not being able to reach up that high in order to save you in time. The only "ladder" that should almost never be working in team play is +3 hit Uair MK combos. The rest with
and whoever else are all fair game.
Well, like I said. It's harder for Bowser to break away from the chaos and actually get up there in order to seal that 85% stock. There's less variance with your Cloud partner to fresh Uair someone off the top at 120% or simply get his 90-100% Usmash off your throw.