I have a theory that 1 hour weight lifting workouts were created by trainers to justify charging their fees. If people just worked out efficiently, a lifting session should last about 20 mins. Trainers have to stretch it out in order to justify their fee.
People are ingrained to believe they have to be in the gym for at least an hour when in reality a lot of the time is wasted.
How long does your lifting session actually last (not counting cardio)?