Gyms don't have to care because they make more money off casual types. Even name brand gyms are corporate and about selling people t-shirts and other crap.
Hard core gyms are probably a lot more difficult to manage. Liability issues, collecting dues from friends, low overhead, equipment costs, financing, upkeep, staffing, taxes, bills, w-comp, business plans, etc.. are all down to a formula when people buy into a franchise.
Finding people who'd be satisfied with nothing but weights, benches, squat racks and maybe a leg press is probably more difficult than folks would like to admit. How many of us would really go to a place that only had equipment for the three main exercises, free weights and a few dumbbells?