I think LG or CM initiated activities are the best time for throwing things in and around a pool. It lets other swimmers know when, where, and for how long they will need to be more cautious of flying objects.
And I'm not against people playing games and pool shenanigans in general if the area is not crowded to the point that your game is likely to impact (literally) other guests.
Here are some actual pool hijinks I have witnessed myself. I'm curious to find people who would not be bothered by them
- A tween aged child would spin in place and then at 'random' chop his hand into the water to send the largest splash possible which ever way he happened to be facing. I say 'random' because he had a knack for dropping large handfuls of water on guests sunbathing well outside the pool. Splashing must be every bit as much a normal pool activity as playing catch right?
- A group of children wearing float vests were playing together near a slide exit and when one of the shorter ones got tired of swimming against the current she would grab on to me or my friend. As it happens my friend is a bit on the frail side and easily jostled, she's fine in the pool up until the point a stranger's kid puts her in a half nelson. When I finally figured out who the child's parent was, someone dozing a few rows of lounges back, she refused to do anything except say, "It's fine" over and over. If being smacked in the face by a stranger's wet nerf ball is normal, getting a slippery hug by a stranger's kid should be fine?
- I was hit by a family's baby. A large, seemed extended, family were playing in the pool and the adults were throwing the children up and letting them splash down. Good fun, they were keeping it within their group and I had absolutely no issue. Then what seemed like an older cousin or younger uncle got involved. This man looked like he wrestled moose for a living. After a couple of the kids got tossed, again mostly within their own little space, it was the toddler's turn; 18 months old tops, a baby. I was probably 15 feet or more away from them, I don't think I was ever even hit by their splashing. This guy lobbed the baby hard enough that it hit me in the back. I felt the face of another persons baby, smash into my back. the whole family found this hilarious and now I'm wondering if I really was a curmudgeon for getting staff to break this up.
- A grown man, whom I have never met, swam between my legs trying to get to a dive-and-retrieve toy. Now I have never told this story to anyone and get the response of, "Well people swimming right up against you is a totally normal pool occurrence." and yet getting beaned in the face by a toy is dismissed as just something you sign up for when you swim sometimes.
- A child was waving his towel around outside the pool. He held it at about the halfway part and he was ... I don't know, just waving it about. He didn't hit anyone and he seemed to be making a minor effort not to, but he came close a couple times as people milled past to get into and out of the pool. The LG immediately shut that down, located his mom, and gave the kid an "official" warning. So I'm thinking back on that now and if I had to choose between getting whapped in the face by a tea-towel sized section of dry pool towel or a wet sponge from 20 feet away, there would be no hesitation.
It's like most people are on board with the idea of keeping your hands to yourselves but put them in the pool and they're fine with throwing things.
I love refreshing just to see what will pop up next 
