I believe the idea is - it is a private pool, open to paying members. They join because they don’t want to go to a crowded public pool full of rowdy kids. I can’t say as I blame them.
The club making a deal with this day camp to bring campers in was a pretty dumb idea. They didn’t consult with their paying members, just jumped in (so to speak). Club members unhappy - I don’t blame them.
This sounds analogous to a local situation I read of recently. I could not find the link but will keep looking.
Some buildings downtown were converted into condominiums. There was some stipulation that along with the condos there had to be included some "low-income" apartments as well. The result was that the "renters" shared the public space with the "owners" and brought their "lifestyle" with them--loudness, rowdiness, hanging out in the lobby at all hours, disruptive behavior, etc. The "owners" began to wonder why they'd shelled out all that money for a pricey condo to live in "apartment" conditions.
I can't say I blame them for being disappointed, either.