Like all art forms poetry certainly has its' gatekeepers, but the situation is no different than that of the music industry, or for painters or illustrators. As mentioned by others here in this thread, I've read work on this site that I found more engaging than that of Pulitzer Prize winners.
With that, I've come to realize that most published contemporary poets are those of a certain pedigree, having gone to the "right schools", and having attended the "right seminars" led by the gatekeepers, or their trustees.
From time to time the idea of releasing a collaborative book of poetry with the "best of DUP" within the pages is chatted up; but the question then becomes: Who decides what's best? ... How many poems get included ... 50 ... 60 ... 80 ... 100? ... and again how are those chosen? Is it from active members ... or from the archives? ... Thus the same cycle we now criticize.
All we can really do is continue to support each other here on the site (how many of you have bought a self published book by a poet you admire? or actively recruited others to the site) ... and relish in the fact that we've got a glorious oasis for writing, and self expression.