I'm not sure why this is downvoted. That stigma in dating is still alive and strong today, and Airbnb is still stigmatized for some of the younger people I know outside of Silicon Valley. Part of the article talks about trust, which is pretty important. Both couch-surfing and dating have lacked identity and trust, which makes it more comfortable. The last thing you want is for someone to axe murder you or spike your drink and not know who it was. If you get axe murdered, knowing who it was is your last concern, but at least it acts as an enormous deterrent. Identity is the reason places like Hacker News don't completely degrade to the rules of Crowd Psychology (well, most of the time).

That friend in Illinois was very uncomfortable with the idea of sleeping in some random person's house, and I didn't realize how absurd it sounded until I was listening to myself explain it to him and his very uncertain reaction. The reputation/trust element removes that "randomness." So much so that I won't book with listings that don't have any reviews, and I tell my friends the same thing.