Earlier quoted context omitted.
The article hits on this, suggesting that they are viewed as communal property since they're so abundant, cheap and frequently forgotten. Umbrellas are also an on demand item, so can see how this could evolve as a sort of community solution to the rain problem.
What is the rain problem? I live in the Pacific Northwest where it rains for 9 months out of the year. Our solution is to not use umbrellas at all. Everyone has a waterproof rain jacket.
So I was getting my hair cut at this cheap place, no appointments, no conversation, you sit on the bench, wait your turn, each time a chair frees up they pop the next person off the queue. ( _alright deque_ ) It's raining and cold, and it's Melbourne so bunches of black wet puffer jackets are dripping off the two coat racks.
person in : black puffer on the hook, person out : black puffer off the hook.
Then one guy starts screaming, 'who stole my jacket? it's a north face, it's a north face.'
He's flipping through the jackets throwing people's clothes on the floor, including mine so I'm a bit unhappy with him and I walk up get him to calm down.
we manage to pair each jacket with it's owner, and we've got one left - a black superdry jacket, with some nice bluetooth headphones in the pocket.
I'd seen the owner come and leave, I suggested he would realise and come back. He could leave his number. He's not happy with this, so I sugest he take the superdry jacket to stay warm and dry, leave his number, and if the guy comes back they can arrange to swap back.
At this point the screamer starts screaming that superdryguy obviously stole his jacket because north face is better, and he's going to take the superdry jacket and the headphones as 'compensation'.
Screams some random abuse about the absent guy as he launches back out into the street (no number left).
Two minutes later the superdryguy is back - wearing a north face jacket, the scene basically repeats with a new idiot screaming, this time that he is going to sue and something about rare headphones.
I don't think this happens in Japan. Must be the umbrellas.