It's locational. I thought the same thing till i actually checked out the local planet fitness. There's just as many juiced up monsters and gorgeous girls at planet fitness as there are at any gym in town. It's also within a couple miles of a huge big ten school.  I personally love planet fitness. The hams usually stick to the cardio machines and the dumb "zones". Sure they don't have "sick" free weights. Building muscle is about isolating muscle groups, putting the muscle under tension, creating a mind muscle connection and damaging the muscle. Muscles don't know weight, only tension. It's proven high rep low weight is just as effetive at building muscle mass as heigh weight low rep. I'd even say it's more effective, just look at most body builders routines.