Eh, space/storage can be an issue, especially if you're in an apartment. And a lot of people want to have that moment where they can talk about how they went to the gym. And a lot of people don't think that far ahead, since they can get a PF membership for $10 right now and per month, since there are a ton of folks who can't think farther than a paycheck. Not that they're necessarily good reasons, but that's a few I can think of.