I think probably the man reason for hangons is the ease of moving a setup. I know that is one of them for me. as the season progresses their pattern changes and they wont travel the same trails. its alot easier for me to run out one afternoon and switch out my hangon and climbing sticks.
I only use a climber when i need to get in to a spot that i dont want to do any trimming or alot of disturbance.
anyone can fall out of anystand without the proper care and safety procedures taken.