I see two difficulties here.
1. Much of the time, it's difficult to draw a clear line between an individual doing normal, unregulated things for which they happen to receive a bit of money and a person acting as a business. If some government official tried to punish me for running an unlicensed taxi service when I give a friend a ride in my car and ask for gas money, the case would be laughed out of court. Is it different if it's someone I just met, say at the airport instead of a friend? Is it different if it's a stranger and the arrangement was made online? Is it different if a third-party intentionally facilitated the transaction?
2. These kinds of regulations seem unlikely to change unless people are actually doing things that arguably violate them. The strategy of getting a large number of individuals to use and/or provide services that don't play nicely with existing regulations is likely the only way a startup has any hope of getting the regulations changed to allow its new business model.
As an airbnb customer, I'd be more happy if they'd properly work on improving the legal situation than playing this silly PR game.
What does this mean? PR is generally how one changes the laws, especially in a representative democracy. I suppose hiring lobbyists and bribing politicians might also work; do you think that's better? By what method would you suggest airbnb work on improving the legal situation?