I think the idea is that your neighbors didn't sign up to live next to total randos. How valid that argument is is up for debate.

And it's not like you can't still rent out to friends or the like. Just totally financializing and anonymizing that interaction turns it into a different sort of interaction. Social trust is a thing, and avoiding having _every single human interaction_ pass through some broker and be financialized is not the worst.

But really... a touch of social proof never hurts.