FWIW, I see far more comments like yours than I see examples of what you are talking about. There is the occasional troll who comes in here with comments like "Cozumel diving sucks" and "all the Cozumel reefs are dead/destroyed", which generates a lot of backlash (deservedly so, IMO), but in the main what I see here are mostly honest opinions.He may be thinking of boosters who sometimes shout down or minimize any criticism of the island. For the most part, those tend to be people with no investment beyond the emotional.
Also FWIW, if I had the opportunity to go to Cozumel in January (I have), I would jump on it (I did), but only as an added trip to the one I take every April or May, not a replacement.