Is verification that tough though? I too have never used Airbnb, but doesn't a person provide CC info? When they get keys from you, they can just present photo ID and as long as A) photo matches person and B) name matches CC, you are most likely clear*
*Unless they've spent the money to get a fake ID in a person's name that they've stolen a CC from - which seems highly unlikely.
The issue is not figuring out whether the person who you communicated with is the same as the one turning up in your house, but rather whether the person is someone you want to rent your place to. Apparently Airbnb hides their real identity from you until you agree a deal, so there's no way for you to check on Facebook etc. whether this person is someone you want to rent your place to.
I really don't see how knowing someone's real identity would help; I still have 0 way to vet them.
What I care about is that there are repercussions (jail, lawsuit, etc) if they do vandalize my dwelling - so the probability becomes near-zero that something bad will happen.
*Unless they've spent the money to get a fake ID in a person's name that they've stolen a CC from - which seems highly unlikely.