Planet Fitness is only useful if you're homeless, not if you're a shitlord who needs place to work out.  If you're homeless and use the gym to shower and store your things, it's a good deal for you, and it's a good deal for Planet Fitness because you aren't using the equipment much and thereby costing them money.  Also, the free pizza nights, etc. are catering to fats, but that's another thing that's useful if you're homeless and burn the calories off by walking everywhere.