Yes, there are some very talented works in slushpiles that don't get bought because of the gatekeeping system. (jakonrath.blogspot.ru)
to get folks to send the entire slushpile to Kindle yet. (jimchines.com)
Those who are substandard, or who publish for fun, will find their titles within a vast, recognized stratum that will be understood to be «the starting point; the amateur slushpile», and there will be several layers above, all heading for the point of the pyramid, if the author wishes to climb. (angiesdiary.com)