Mike Hearn is also the guy that is proposing to build blacklisting into Tor, as well as reduce the fungibility of Bitcoin with built in taint tracking and rejection.
What is wrong with a tor node wanting to block something going through their computer and network? It is their connection you're using and are under no obligation to forward any traffic to you in the first place while they risk themselves, and you're still free to use a different node.
Because it's fucking TOR. Why are they operating a TOR node at all if they want to block shit? That's not what TOR is for. They should take their computer and their connection to a different network.