Interesting theory. I'd like to hear from experienced judges if they find this to be true today.
Compared to five years ago, I think with the better ingredients, equipment and knowledge we have today, there's a lower percent of poor quality beers being entered across the board.
I'd guess that if there were 5 mead entries and 50 IPA's, you could get one bad to mediocre mead and 10 bad to mediocre IPA's. The rest being good to outstanding by BJCP standards (over 20). There's a good chance I'm wrong, so hearing from someone judging would help.
When you throw palate fatgue and inexperienced judges into the mix, it can become a crap shoot getting a beer through in a big category. 3 out of 8 will never compare to 3 out of 53.