I stayed in one AirBnB where there was a book on a shelf in the living room. I opened it, and it was the name, passport number, date, and some other information I can't recall for every past guest.

It's a risk vs reward scenario. The data leaking from Airbnb is bad, but nowhere near as bad as the data leaking from a porn site. You might be willing to take the risk with the former but not the latter.

The main damage here isn't the data leaking (it's already out there thanks to countless other breaches anyway), it's the data leaking and the association with the porn site.