I am going to weigh in on the buyer's side, since Nick and Mike are two of my favorite sellers. From a buyer's perspective, the rules here create a kind of safe harbor where you don't have to be defensively looking over your shoulder all the time. It certainly is no utopia, see e.g. probation thread , but it is filled with very good sellers with very good books.
I have been fairly active here almost 18 months and have seen more amazing books in that time than I would have believed. Were money no object, i could have obliterated my want list. And the best thing is that it all genres. I don't have any problem tightening things up here a bit. But as a buyer, I am afraid that loosening it up will kill the special quality it has.
--Sean.