It's sadly a lack of education. There are a so many people who get sucked into buying their babies at flea markets, malls, garden shows, etc. We all know the glider mill's I'm talking about. Unfortunately, these places also give terrible information.
Other people probably just don't realize that gliders are not like hamster, or guinea pigs, or bunnies. They probably think if they bathe them, it will get rid of the stink. The rest of us know that 1)gliders smell when the cage needs cleaned and 2)males will stink if not neutered.
It is sad and I find myself commenting on these videos to try and tell people, no, it's not funny to watch your glider scrambling to get out the water, he's not swimming, he's drowning. And no, it's not funny when they run in circles and do backflips, he's not playing, he's going crazy from boredom and loneliness. I saw one where this young guy was taking his glider and throwing it into the air and catching. He was laughing because he thought it was funny how the glider would put out all 4 limbs and spread his little flaps out. My comment wasn't very nice. I think I said something like, "WTF is wrong with you?! He's not flying, he's terrified. Gliders have a fear of falling, what you are doing is abusive and cruel."
I was pretty ticked off about it.