I was talking to someone about portability. As tricky and random finding pianos might be, compare to something like a guitar. If you’re away from home, how likely is it to get ahold of someone else’s guitar to play? It’s a much more personal instrument, with configs like strings, straps, tuning, transportation, potential damage. How about a saxophone or violin?
But with no forethought and not carrying anything, if you find a piano, at a friend’s house, a reception room, a church or an airport lounge, you can sit down and play. You’re portable.
It’s a bit of tortured rationalizing, but an entertaining notion.