A hetero gym would probably have taken action if you had complained. But if many of their customers are gay, then they’re that kind of gym, and they’re not going to do anything.
The membership shifts over time in my experience. You join a nice well kept, well run gym and it goes well for a year or even several, then the equipment starts to slip a little, they’re not as particular about who they allow to join and then the homosexuals hanging out in the locker room follows. Then, they go out of business.