They publish a list of exit nodes yes.

Even if they don't, it can be determined whether a particular node is an exit node on Tor.

Information which can be used to selectively block access to those connected to Tor.

That way, you are correct. 

Still better than a VPN because there is no entity to go after, since the code for the protocol is open source.

The weakness you mention exists by design and can only be addressed by being censorship-resistant on an ISP level.