As I understand it (as I said, I still have to look this with more detail), the access to the blockchain is not controlled by anyone, this portal "steemit.com" is only an interface to interact with the blockchain, so theorically there is nothing that can be done to stop bots :(. It can be limited through this interface though which is "easier to use". Although it's true that creating an account seems to require some kind of validation, I'm not sure if that's only part of this portal or the blockchain itself.

But yes, it definetly looks promising regardless of that :D.