Brendan Halpin on the "likeability trap" and YA fiction. This apparently increasing phenomenon -- character "likeability" as the central, most important criterion for assessing literary merit -- is one of my least favorite things about the democratization of criticism enabled by the internet. (I assume the internet is to blame for enabling it, at least as a self-validating cultural tendency among readers who post stuff on the internet.)
Brendan's caution that we'll "miss out on some cool books" if editors begin to take their cues from goodreads, et al. and reject books with complex, disreputable, or politically incorrect characters is apt, though I doubt we'd see that taken to the extremes he fears, if only because the resulting books would be completely boring. I still have enough faith in readers and humanity (I know, I can't quite believe I typed that either) to have confidence that such books would eventually weed themselves out. In the borderline cases, though, it's a pressure I can easily imagine could exert an undesirable influence, in the spirit of going along to get along, e.g. toning down a character's vocabulary or unsavory thoughts or feelings in hopes of getting a few more five star and a few fewer one star reviews from random people on the internet.
The more plausible danger is increasing self-censorship on the part of authors, who, having their characters and books slapped down and dismissed time and again by the likeability brigade will inevitably consider shying away from the unfortunate habits that earned the slaps. Authors are just like anybody else, only more so, in craving approval, and moreover in the aggregate these reviews can, it seems, be not insignificant in determining commercial success or failure of a given book or writer. This sort of self-censorship is already a big factor, it seems to me. I think it was Flannery O'Connor (was it?) who described her relationship with her readers as primarily adversarial, and most writers know what she was talking about. This goes with the territory, of course, but it can be exhausting, and the temptation to pull punches and tailor your writing to make it kinder and gentler (and weaker) can be hard to resist. It's one reason characters tend to be so "samey" these days, in YA fiction as well as in other marketing categories.
I'd love a world where "unlikable," challenging, or complex characters were appreciated and celebrated, and seen as the mark of good writing rather than as an indication that the machine has broken down and failed to deliver the warm, fuzzy goods. In fact, that is more or less the world I grew up in, at least as far as literature courses and old style book reviews went. I don't remember any lit professor ever asking me to write an essay on whether Stephen Dedalus or Raskolnikov were "likeable" (though I suppose they aren't.) Has this changed? You know, I wouldn't be too surprised to learn that it has. Dislike.