I grew up always using the safety bar, but over the years I’ve realized that as long as you aren’t doing anything reckless, there’s nothing wrong with leaving the bar up if you’re solo or with others who don’t mind the bar up. Plenty of lifts in the West/Midwest and elsewhere around the world have no bars and there’s nothing fundamentally wrong with them, otherwise they all would have been retrofitted with bars long ago. That said, I do think it makes sense to always lower the bar (if available) if kids are on the chair.
Nowadays, when I’m riding a chair by myself, I’ll usually put the bar down for no particular reason other than habit. If I’m a single riding with strangers, I’ll ask them after sitting down if they want to put it down or leave it up and mention that I’m fine with either way. That said, I can think of at least one lift ride where I was the only one on the chair and got distracted by something I saw right after loading, and didn’t realize until halfway through the ride that I had completely forgotten to lower the bar!
Like @riverc0il, I am normally more comfortable with my legs hanging loose rather than on footrests. Especially if I’ve just skied a mogul run or glade, it’s nice to let my legs hang limp and relieve the tension.
