>>49460621They banned it from ubers even after having a clause that banned individual pokemon from dynamaxing. You could say that same thing with megas and z-moves in terms of changing the battle mechanics. People sometimes mentioned how the meta revolved around your mega pokemon. If I recall z-moves was especially controversial, but preserving the identity of the generation was an important enough reason to keep those mechanics.
Even if we assume it didn't have anything to do with balance, dynamax was still enough to dethrone mega-ray as seen here
>>49457721It's not just the hp increase, but the moves, immunity to a bunch of other stuff, and combos with items.
I think the vote for double was also borked since they tested weakness policy at the same time. Looking at their votes, if they used a different voting system, it might have been weakness policy that would have been banned instead.