I think it's more about the general stance that OSS is in general technically superior, than about particular projects. The problem that must be "explained away" -- according to the article -- is not a particular flaw of a specific project, but the observation that OSS is not, in general, technically better.
TFA states that OSS, by claiming it's technically superior, must defend itself when it's not superior. On the other hand, FSS must not defend against technical flaws or limitations because it doesn't claim it's technically superior, only that it respects user freedoms better.
TFA states that OSS, by claiming it's technically superior, must defend itself when it's not superior. On the other hand, FSS must not defend against technical flaws or limitations because it doesn't claim it's technically superior, only that it respects user freedoms better.