Jejudo, South Korea
At first glance, I would agree with you. The quality of writing is/was higher than here. As I participated, however, I increasingly began to feel that the negativity was seeping into the poetry itself.
It may have changed, I don't know, but the more poetry I read there the more I realized that a certain diversity was lacking: a focus on the poem of the picture, and not of agency. This makes sense because agency all too often leads to sentimentality (a big no no from their point of view) and far too easily attacked for any of a number of reasons. This focus on negativity, on a misplaced use of objectivity, and, quite often, a misunderstanding of tradition/history (and these are all intertwined) has led to the exact same problem that occurs with too much emphasis on positivity: an increased reification of language.
And that goes against the very poets and poetry that they profess to admire.
Whatever initial constructiveness negativity can bring (and I do think it can be constructive) was squashed underneath the weight of an overpowering sense that the site really had very little to do with getting better poetry and much more to do with following an unwritten rule book.
That is, the same type of poem every time (I'd give you examples but I was banned -- for certain childish acts on my part, yes, but no more childish than anything I saw there. By the way, when I was posting there, comments directed at my stuff were, for the most part, quite positive.).
This may be quite unintentional, it may be simply the result of hearing the same defenses time and time again (I know the feeling), but I saw no self-reflection, I saw no sense that the negativity was in order to improve writing. It seemed to me simply the result of exhaustion.
Or the result of reading the rule book without really understanding it.
I don't know the causes, I can only give you my impression but I think it's wrong to assume that that site represents:
"good poetry written by serious, intelligent, creative people devoted to the craft and art of writing, and that's the goal of the 'other' site."
True, I can't point to Pip as a site that better achieves this goal, the excessive positivity seeps and influences the poetry as much as the negativity does there but that's really my point: neither site really furthers your goal.
Only individuals can do that.