The Hot 20 seems to be such a source of discontent that perhaps there should be an opt out of the vote, just as there is for comments and ratings. If an artist knows his work won`t be voted in, then he can content himself with the thought that it would have been if....
I know this will negate the point of the whole idea but the thing is so open to abuse it seems pointless anyway and if artists are leaving because they feel their work is being denied inclusion because of "popular" voting, it is counter productive.