There are two answers to this I can make, which I will, here.
First off, there is one crucial difference between himself and his example of Leonard Nimoy. Nimoy is, indeed, not Spock (though he has published a second book, I Am Spock, that sheds more light on the subject). However, when he is playing Spock, he generally is not performing lines he himself has written, or as a character he personally designed from start to finish. Mr. <redacted> is.
The difference comes when one considers that online actions have real-world repercussions. Those repercussions are someone's responsibility. In this case, there is no practical difference between Mr. <redacted> hurting people himself, and having his online character - whose lines he alone writes, and whose character he alone defines - hurt people. A difference that makes no difference is no difference. Put another way, I do not care if it is his character that is an asshole, for only an asshole would have his character behave that way to other people.
Secondly, he speaks of respect. I do believe that there is a certain, basic level of respect due to others. However, I also believe that that respect can be forfeited, just as it can be augmented, all as a result of others' actions. In this case, he has indeed forfeited any and all respect he may be due from me by his intentional disruption of #WarnerCafe. He says, in this comment to the entry explaining why he banned me from his journal, that "the worst thing I've ever done in the past five years is make comments about his political views". He is wrong in this. My complaint is the one that wbwolf makes about me: it is not his comments that I object to, but the manner in which he makes them. He does so in a manner designed to infuriate me, knowing full well the reaction he will provoke if he only keeps it up long enough. That is not the act of a person I believe is deserving of respect.
He may believe that he is now free to not show me any respect in return for my perceived disrespect. He is wrong in this only in that it is not a change for him.
One final note: He says the transformation from his original character to his current one was brought on by his realization that online actions have RL consequences. I fail to see how he has truly learned that lesson. If he had, he would not act as he does.