Part of what may be going on here is some selection bias in the assignments, where Cotter and Smith get the most prominent shows to review, while Johnson and Rosenberg get the next rung down, thereby getting a more mixed bag of quality, and leading ultimately to more negative reviews overall.
But regardless of how we interpret the data above, in our own efforts this past year or so as reviewers of photography shows, I have come to believe that the negative review is the toughest article to truly write well. The challenge is that it is temptingly easy to be flippant, sarcastic, snarky, and generally make fun of bad art or poor curating/installation (and readers certainly find it entertaining when a good zinger is launched); it is altogether harder to show respect for an artist's (and curator's) work (however bad it may be) by giving it a thorough and thoughtful analysis that finds it systematically deficient in major areas. In these cases, the siren song of crafting a bitingly clever dismantling is oh so tantalizing, and yet I think in the end, this approach is ultimately counterproductive.
Why is this the case? I often receive emails from readers who ask why so many shows receive one star (GOOD) in our rating system, and why there are no zero star shows ever reviewed; surely there must be plenty of boring and awful photography on view in a city as large as New York. If you are the NY Times, and your mandate is to cover the best/most important of what's out there, it isn't particularly surprising that there aren't many negative reviews; in this case, a negative review is only needed when a big/important show is found to be severely lacking, which doesn't happen all that often. This type of negative review is an unmasking of an imposter, where both the artist and venue are generally already successful enough to know better, and should have thick enough skin to handle the feedback.
In our case, since we review photography shows out on the edges a bit more, including many first solo shows, we certainly come across plenty of astonishing clunkers. But in general, we have decided that omission (via no review on the site) is a better punishment for these shows, as opposed to a harsh or diminishing tirade, which may forever haunt the first Google search page for an emerging artist. This is not to say that we are not openly critical; regular readers here will hopefully realize that we do our best to be even handed, and to highlight areas of weakness we see within the larger context of the exhibit or the artist's career, particularly from the subjective perspective of a prospective collector of the work. We have to be balanced (good and bad) or we will lose the trust of our readers.
It's of course a tricky balance. No one wants "grade inflation" or a mass of content-free glowing reviews that parrot the unreadable press release text; we all want real eyewitness accounts of what's on view, with a dose of concise, realtime, critical thinking applied to these shows. If the work is uninspired or derivative, if the prints are lazy or fundamentally flawed, we want to hear about it. At the same time, it is our view that we also want to continue to find ways to encourage artists whose show today may be marginal, but whose next body of work may be transformative. This implies a careful toning down of the rhetoric, so as to find a higher percentage of silver linings rather than scathing dismissals.
Perhaps this desire to have it both ways is a result of our position as a commentator from within the photography community (as active collectors), rather than an objective critic from the outside. In any event, I have no definitive or "right" answers to these issues today, and therefore leave it to the rest of you to consider the rightful place of the negative review and whether or not we have found the appropriate balance in our efforts here.