A point well-taken indeed, but...the uber-lefties will occasionally get called down/out by the more centrist ones. I don't recall a similar thing happening with our departed guest, except for maybe one or two things of yours towards the end. Maybe there would have been more to come. I'd like to think so.
What totally bugged me was his adressing everybody not on his page as "leftists", "socialists", "statists", whatever and then attributing all sorts of absolutist "motivations" to any disagreements with his rather absolutist "libertarian" attitudes. There was no room for nuance with the guy, no room for partian agreement or disagreement, and no looking at anybody as an individual rather than a "type". It was a like dealing with a Wynton fanatic...
It was also the introduction of an idealogue rather than an idea, and the further it went on, the further it became obvious that this guy(?) was here, not to debate or introduce ideas, persopectives, and concepts, but just to put a label on everybody who would disagree with him and then use that label as a springboard from which to proclaim his idological superiority. We've had leftist trolls take this approach from time to time, and they've been banned too.
The guy never allowed that he was dealing with nuanced individuals here. Whethre that was becuase he was teminally myopic or just a "posture" on his part, it grew old quickly, and never produced anything other than YES! NO! YES! NO! YES! NO! ad infinitum. His banning is no loss at all to intellegent, or even semi-intellegent, dialogue.