They’re all men, and their mean age appears to be about 55. This is perhaps not surprising given the age and gender of the editor-in-chief.
Now wait a minute—being in your 40s and 50s and 60s is no problem! It’s actually a very sensible age. The lack of female input is a serious shortcoming, but let’s not give people grief for their commendable longevity and long-term activism. (Also, Martin seems to have missed that young whippersnapper, Chris Mooney, who has a column in the magazine.)
The problem isn’t old people: it’s the lack of diversity. When I see the list Martin puts up, what I see is a group in trouble, one that has failed to extend its reach beyond the fairly narrow circle of its founders, and one that is going to fade away as that group dies off. As he notes, it also means the magazine acquires an old-fashioned tone that is going to fail to bring in new blood.
He recommends Skeptic magazine, to which I also subscribe, and which definitely tries much, much harder to extend its reach—it has a whole section, the Junior Skeptic, specifically for kids. My one complaint about it is similar to the one about SI, though: sometimes there isn’t enough diversity, because there’s too damn much Michael Shermer. Nothing personal against the guy, but sometimes it does seem like it’s a glossy magazine dedicated to showcasing Shermer…and that also has perils for long-term viability.