The world has always been full of random verbal noise. However, starting about a century ago, the volume seems to have steadily increased.
A poem, on the other hand, is surrounded by a kind of silence, like a town just after a very heavy snowfall. This is because a poem is a kind of distillation - the precipitation or extraction of an essence (from within the noise).
The judges & critics of poetry should be on the lookout for these distillations. They are the actual poetic record or canon (recognized or not) of their times.
I think a poem is an act of balance, equilibrium - a conjunction of opposites. Both. Unique and common; original and final; personal and universal; individual and representative. It is both sui generis and an example of a class, a period. It is new and old. It is experimental and traditional.
We laugh and deprecate anthologies, canons. But they are part of the critical and self-critical labors of the culture from which they emerge. The point is to form your own true canon out of all these efforts - and in spite of them.
A poem, as an act of equilibrium, is also a display of a positive kind of disinterestedness. In this sense, a poem should show, not tell; imagine, not lecture. If it is going to lecture - and some poems must - it should provide authentic poetic evidence (in terms of both style and exempla) for its arguments. A poem should reveal something - and let the readers exert themselves (to draw their own conclusions).