I've had long hair since I was about 12 years old except for a brief spell in my late 20's or early 30's when I had a bob. My main problem then was that I overheat badly in hot weather and need to clip or tie it up otherwise I have wet hair round my neck which feels horrible.
My mother wouldn't let me grow it long as she was convinced I'd be more likely to get nits, and said "You can grow it long when you go to grammar school as you'll be with 'cleaner girls'!" We now know that nits prefer short hair, probably because it gets less brushing! As a result short hair seems like a punishment to me.
I too have very thin hair but my bald bits only really show when I get really hot as I sweat, and the wet hair separates and no longer covers well.
I don't think my long hair looks awful at 67 though long hair does on some people. A few years ago I met a friend I'd not seen for a long time and she'd gone very grey. Her very long hair made her look a bit like a witch!
I'm not sure if I'll ever have the courage to go short again, though as I get older the overheating does seem slightly less of a problem, so maybe.