I agree with David 100%. The problem is that some is good, but not to my taste. Those are the tough ones to reject. The easy ones are the spam submissions of rhyming poems about how Jesus is LORD. Those break two of my very few submission guidelines.
I can imagine that the last thing that Buk would have wanted to do is read the type of submissions that you get when you do an open call for submissions.
Small Press Review is a great resource and Led Fulton is a small press hero, but the only down side is that there are poets that start at "A" and work their way to "Z" sending submissions. It would be better to target the audience. I can't tell you how many submissions that I get mention that they bought and LOVE my magazine. The only problem is that I cannot believe them all as I have not sold enough to explain it. I think that they are trying for an "in", not having done the research.
With someone like Bukowski, I cannot understand why he would not have just asked the people that he liked to submit. It seems that the open call was something that was destined to fail with him.