In a perfect world, a publication is edited for readers. In the imperfect world that we inhabit, too many publications are edited for the benefit of their staffs and their friends and associates.
The particular culprit he has in mind is The Washington Post op-ed page, but the point applies more broadly. Of course, staffs and friends and associates can provide the psychic benefit of professional esteem and approbation, not to mention the material benefit of access to future employment opportunities. Compared to that, what do readers have to offer?