Agreed. Small sample size, but my wife used airbnb twice in london. First time was good (not great, but good). Second was
horrible. (no curtain on windows directly facing office buildings, broken shower, no tv, 2 hangers for a 10 day booked stay, etc). Video evidence for everything, and multi-day delays in getting resolutions (everything documented via their platform). Requested a partial refund (no working shower for 4 days?) Response was a resounding
no, then threats from the person who was doing the renting that they would post negative reviews of my wife as a renter so no one would rent from us again. Guess what? The owner (and his girlfriend) had several airbnb properties they were renting out, growing a landlording business (without all the pesky regulation). (edit: there were multiple reviews stating how great it was - it was a veritable dump - which is partially ok, but broken shower, no tv, etc - when those are clearly listed amenities - is simply lying. Oh, and if you're going to rent out a room/place via airbnb, please remove moldy/stale food from your refrigerator first)
Contrasting that with a recent nashville visit via airbnb (I didn't book it, but stayed there) - the epitome of the "share my home" aspect that gets played up - notes around the house, everything fresh and tidy, etc).
Forcing just 1 would certainly get back to the roots. Or perhaps a sliding scale - fees go up as you want to list more rooms? The individuals wanting to rent out a spare room get the cheapest fees - the people trying to be the next hilton (sans service and regulation) pay correspondingly higher fees).