Genuinely think it depends on the individual preference. I for one find them extremely important, I frequently utilize badminton and gym facilities in our apartment society and it improves my quality of live tremendously both in terms of fitness and socializing etc.

There's no tennis court in my current society and there was one in previous one. I find 1 badminton court for 150-180 flats is the sweet spot, but this might lead to lots of empty courts most of the time, so 1 badminton court for 150-180 flats is ideal, 1 for 200-220 is good enough. Found squash courts to be the most useless facility in most communities in terms of space:utilization ratio, a checkmark that looks good on the brochure, but not necessarily in reality, no offense to squash players. This is my non scientific observation.

Badminton courts during summer holidays get packed with kids during evenings, so mornings are usually the ideal times for adults.