Let's make a list of people who embarrassed themselves by reacting with support of violence after 9/11/01, and those who were vilified by specifically NOT doing so.

Category 1:
Christopher Hitchens
Robert Thurman (a leading Buddhist scholar)
I don't know about his immediate reaction, but Martin Amis clearly belongs here for being so dismissive of people who want to see things from the perspective of, say, Hezbollah.
Add on?

Category 2:
Susan Sontag. I know people who have still not forgiven her for saying that you can't properly call someone a "coward" if he deliberately flew a plane into a building. She said you can call them a lot of names, but "coward" isn't one. I don't think she ever fully recovered from the slings and arrows that she aroused with that.