It all depends how far someone bends their legs. Most do leg presses with little shallow knee bends. It takes a lot of effort to put the back board low and completely bend your legs with four plates. Anyone can pile on the plates even old ladies if they do shallow leg presses.
Very true, it's a typical ego exercise and most guys are rather weight driven than muscle-minded driven.
Another factor is that there isn't a gold standard for leg press machines. So far I've trained with at least 10 brands and all of them had different angles, platform weights/dimensions, mechanics, etc. I rarely perform them anymore and focus on deep squats, deadlifts, glute-ham raises and some leg curls, extentions & adductions as finishers.