This was probably necessary due to instances where someone rented an AirBnB apartment under a fake identity, and then proceeded to completely trash the apartment.

In cases like this, where anonymity allows users to cause serious damage without repercussions, I don't think identity requirements are problematic. However, extending this to harmless actions like commenting online is a completely different thing.

People can use commenting to call for genocide or push people into suicide, they can use communication to plot terrorist attacks, etc.

The only difference is that it is not physical damage.

I support anonymity, I hated what Airbnb made me do in terms of insecure exposing of my identify to them (and then had I use an empty gmail account to verify in the end).

I don't understand how you can expect to be anonymous in a service where the point is to physically show up. There are all sorts of practical safety considerations that don't apply to other services.

I feel perfectly comfortable giving even intimate details directly to the host. But I did not feel well sharing them with AirBNB itself.

similar thing for Airbnb China. They ask for National ID and fullname then run ID check. I was surprised and thought it was a chinese thing. Look not..