Completely agree. AirBnB de facto bribes you to not leave negative ratings. Last cancellation I had was from a no-show host, who left me without a place to stay in Canary Wharf in London, had to shell out AirBnb price + $100 for a last minute replacement, minus the 3 hours I spent waiting for the host (she was mysteriously in Russia instead of London). Host wouldn't give me my money back unless I promised not to give a bad rating. AirBnB offered me a $50 credit for my next stay. W00t.

Guess what? That no show host still has perfect ratings...