Why? Did thet expect Luffy, the punching guy, to not win by punching? I get that Oda's old comment set expectations for it being different but how is this defeat any worse than al the other wins he and since chapter 1?
It's not the attack that's bad, it's the context behind it being the final attack that sucks.
-Kaido and G5 Luffy's battle transitions into the Bajrang Gun way too quickly and without much of a setup, to the point that a lot of people just assumed it was gonna be another G5 attack for Luffy to show off, just like went he went giant.
-Kaido's backstory being rushed a delegated to a third of a chapter.
-That same lack of backstory has the effect of us not understanding Kaido that much as a character, which means we don't know if Luffy got a "philosophical" victory over him or not, like he does against other major antagonisst. This is something that Oda usually nails, all the way back since like Buggy. Seriously, if anything this victory probably just validates Kaido's view on the world being all about survival of the fittest, and we still don't understand fully just what Kaido's own philosophy on death even is.
- Even what was supposed to be Momonosuke's BIG moment, making the flame clouds, is gone by in an instant and no one from the flower capital ever even sees him do it, it just happens in a few fucking panels and it's done. They never get to see 2 dragons in the sky or be afraid of Onigashima falling down. Compare this to like, just how much anticipation there was for Doflamingo's defeat back in Dressrosa and how satisfying it was to finally see Luffy land his final attack and win.
my spoilers 
