Everyone says AirBnB was a bad idea, but only the original idea was bad. Once you realise that the business is really about running illegal hotels where the risk is outsourced then it becomes a very good idea.
The original idea was for people to share their home or room to strangers. This was not a good idea, but pivoting into the illegal hotel business where the properties are continually rented was a good idea - at least until there is a major crackdown.
No, thats exactly why I'd say it was a bad idea, because who would accept that outsourced risk?!
(It turns out a lot of people did)