Swim diapers do very little to keep pee or dissolved feces in them. They are there to keep turds from floating away long enough for a parent to take care of it.
Also, how many dirty assholes are getting cleaned by the pool water? That dude that was just grunting in the stall of the locker room likely didn't wash his ass before jumping in.
Makes sense, not sure why other countries don't do the same. I'd much prefer fewer chemicals in the water and a required shower than the current system in the US.
That's what I do after spending time in Finland.
The funny thing is, everyone else in the pool looks at me like I'm crazy for showering and using soap before I get in the pool, they just get themselves wet in their swimming trunks before going in.
Also, how many dirty assholes are getting cleaned by the pool water? That dude that was just grunting in the stall of the locker room likely didn't wash his ass before jumping in.