And another major point is, what do DPers actually want to work on?
Hard material tends to go through slowly, where as junk fiction tends
to go through pretty quickly. That has nothing to do with the
popularity or worthiness of the text. We could toss out a bunch of the
"less worthy" books in exchange for the OED or porn, but I doubt that
will increase DP production overall.
This is at least due to the urgency DP places on moving people out of their
comfort zone.
New people at every level are encouraged to choose (naturally enough) easy
projects to climb the learning curve; and since virtually everyone is being
encouraged to advance, this material comprises a larger portion than it
would otherwise. To assist this, easy projects are released from the queues
more quickly (again to encourage new skills).
I've mentioned that no Shakespeare play has been released into F2 or processed
into PG for several years, despite sitting in the F2 queue much of that time.