I think it's a pretty responsible practice, although perhaps a bit extreme in regard to membership cancellation. Maybe instead they should make you clean the bathroom for a week, or go stand in a corner.
The Powerhouse I go to has the same rule. When I went the the local YMCA, there were no such rules, and there were many, many pigs. Nothing sucks quite as much as when you're trying to progress through a workout, having to spend 5 minutes wandering around the gym floor looking for the set of dumbells you need that some inconsiderate mook didn't put away.