You are correct about the editorial. Cockburn would agree and Hitchens has repeatedly pointed out that in '92 Clinton ran to the right of Bush on both Israel and Cuba. You are right in saying something in every issue will infuriate us radicals. If you don't want to spend money on that, fair enough. However, I don't understand your need to trash the columnists. Alterman deserves it, yes. Pollitt has slammed him. In his book "The Golden Age Is In Us" Cockburn described him as "Quarter cheeky-chap, three-quarters brown-noser." This after Alterman, in his book on pundits, had called Cockburn "the world's ... most infuriatingly rigid Marxist journalist."
I've always enjoyed John Leonard; name dropping can serve a purpose that you may not see from your perspective. For a young person who's ignorant about the left, it can point to further reading. I began reading The Nation at age 23 after Clinton had defeated Bush, right around the time they had the awful cover story on the end of socialism. What impressed me was the numerous lengthy, well-written letters to the editor denouncing the piece. Even if it has moved to the right since then, the magazine has also provided me with a valuable education. One should recognize that it is forum and the dialectical method is a good way to go about learning the issues. The "redefining liberalism" pieces drive me to distraction, but is it unlikely that a few liberals reading the magazine have been moved to the left? Basically, I just don't agree with your characterization of the columnists.
Peter