This thread has been going over pretty much the same ground as the Eragon thread, so I've kept out of it for now (although I waffled on at great length in the other thread). A couple of points seemed interesting enough to warrant further comment, though.
I thought the yummy/nutritious analogy above was illuminating. It echoes my own thoughts on the subjective/objective divide regarding writing (or other artistic endeavours). Technical aspects of art are certainly objective (musical harmony, grammar, spelling etc). This is pretty cut and dried.
Aspects of dialogue, plot, characterisation and structure are also basically subjective, but acquire a strong degree of objectivity through collective appraisal. In other words, although some people might like aimless plots or bland characterisation, the collective view on these things takes precedence, allowing for literary analysis and criticism. I called this an "objectivity by the masses" in the other thread, although it wasn't applied directly to art in that example.
On a personal level, though, appreciation of art is ultimately a subjective experience. This is borne out by the fact that people can enjoy bad movies, take pleasure in cheesy pop songs and lovingly collect penny-dreadful comic books, just as they can find supposed masterpieces utterly unfulfilling. For the individual, this renders arguments about good and bad art somewhat irrelevant. Any objectivity can be trumped by the tastes of the observer (and vice versa, for the sake of argument). That doesn't mean that objective analysis is itself meaningless, just that it can stop being meaningful to an individual when the whimsy of taste takes over.
This is why it is possible, acceptable and right to be able to be curt, dismissive, adoring, ecstatic or disinterested about anything that you feel deserving of that treatment. You can rubbish any piece of work that you like, without needing to feel like you are being rude or deficient, or that you have to say or do "something clever or insightful instead". You can praise the trashiest romance or most hackneyed Tolkien rip-off. You can go "meh" at the latest chart-topping platinum wunderkind or blow your savings following Jessica Simpson around on tour. At the end of the day, objectivity or not, all you have is your opinion and people who try to deny you it are dullards of the worst kind.
To move the discussion on:
Something that I am noting about Merlion's approach has, I think, little to actually do with art itself. I have noticed on several occasions that Merlion insists that art has a merit of its own, simply because someone created it. If I might be so bold, I suggest that what Merlion is saying here is that people have an inherent value, which they impart into their creations. Art is inherently valuable because it was made by a human. Correct me if I am wrong, Merlion, but that is the message that I am getting, and it seems to have been somewhat lost in the back-and-forth about objectivity/subjectivity.
If so, I'd like to add fuel to the fire by saying that I'm not sure that I would agree that art is inherently valuable because it was made by a human. Largely because I am not yet convinced that humans themselves are inherently or equally valuable....