Planet Fitness's whole business model is setup to cash in on people who are the type to get a membership in January, go for a few weeks and then not go until next january while forgetting to cancel their memberships. The owners of Planet Fitness have admitted this in so many words in several interviews. Its not meant for serious people but those who go to a gym on a whim after thinking "maybe I should work out
" and then give up.
People who are serious about working out come everyday, use the machines which drives up maintenance costs, which in turns cost Planet fitness money. The do everything to discourage those people from coming. This is why they don't have dumbbells over a certain size, no squat machines and even have something called a "lunk alarm" if you make too much noise while working out.
Its a literal alarm that goes off if you make too much noise
Also their commercials let you know where they're coming from .