I don't know if I'd put it quite that way. It is an attack on the author, but attacks are not automatically invalid. We must ask the question "Was Soghoian's attack legitimate?"

I could comfortably answer yes. Soghoian could not come up with a reasonable explanation for Quinn's decision to not publish criticisms of the program. He therefore hypothesized that the author simply did not respect the people offering the criticism. He then produced a quote from Quinn which would support that hypothesis. If Soghoian were incorrect in that assessment, the Wired response should have pointed that out.

We must also realize that this means Soghoian isn't quite right in claiming his first criticism was about tech news in general. He did specifically criticize Wired, and therefore Wired is well within its rights to respond. Wired's allegations of sexism, however, was definitely not legitimate.