It's kind of a stupid custom, and as Frank Schwab of Dr. Saturday points out, a voter who is influenced by such things shouldn't be allowed to have a vote at all.
Regardless, there's one potential Heisman candidate next year whose school won't be campaigning for him at all, if he gets his way.
Louisville QB Teddy Bridgewater, who is widely considered the best QB in the country and potentially the #1 overall pick in next year's draft (if the top team can resist the temptation of JaDeveon Clowney), has said that he doesn't want Louisville to bother lobbying for his Heisman campaign.
His reasoning: He doesn't want them to focus on promoting him as an individual, he would rather have them promote the team as a whole.
This is exactly the kind of thing every coach wants to hear from their star QB. Bridgewater (and everyone else) knows that the spotlight will be on him, and he'll be getting plenty of attention regardless. But his goal is to bring the team together and highlight the efforts of his teammates.
Lots of players talk a big game and say it's all about the team, but Bridgewater had a chance to prove it with his actions, and he stepped up big time. Kudos to him for putting the team first.