I think I can add to this subject... okay, I will start by saying I'm not a poet, I'm involved in visual art. And I will state that I don't fundamentally disagree. However, I do have some questions. are not the metrics by which you measure the quality of a poem the subjective interpretations of individuals who created rules for what a good poem is? If so, what is it that allows these individuals qualified to make that distinction? It seems to me that style and form go through motions throughout history. These shifts in mass perception of art are expansive, and impossible to trace the catalyst in most cases. Currently, shifts in the lexicon, and an eroding public education system (in the US at least) may account for the interest in a less complex form of poetry, one which is more accessible... even understood by appealing to instinctual emotions instead of intellectual ones.
Also, I would say that people often like what they are told to like. I see this most radically in the CIA funding of Jackson pollock as a means of countering Russian realism, and establishing the US as a cultural center during the Cold War.
Van gough also illustrates this, hated in his life time, beloved after. Was his art good or bad? Depends on when you were alive.
Is Kanye a good lyricist? Does he write his own lyrics?
But perhaps the only problem with labeling something as good or bad is a semantic one. How does an objective qualifier get attached to a subjective piece of art? How do you define good and bad? Does it have an ethical implication? Perhaps it's more accurate to say I like this, or I don't, for so and so reason.
Anyway, thank you for bringing up this subject, it's something I think about a lot! (Don't get me started on implied, perceived, and intrinsic meaning...) I hope that this topic will continue to be openly discussed here, I enjoyed reading all the comments! I will be following you for more!