Just to clarify, Pete Rose isn't kept out of the Hall of Fame because people think he's a bad guy. He's kept out because he broke a specific rule, one that is posted in every Major League Clubhouse, and one that effects the integrity of the game itself. So it's not neccesary to think Rose's bets are a morally worse offense than Babe Ruth's appetites or Ty Cobb's nastiness.
Also, betting on one's team is problematic, because as manager, Rose had the ability to influence which games the Reds won by his decisions about, for example, an ace relief pitcher. Is there specific evidence that this happened? No, but that's not the rule. The rule is you can't bet on games in which your own team is taking part.
Now, as Rob Neyer notes, maybe betting on your own team shouldn't be a hanging offense, and I have some sympathy for that argument.
What is true is that it doesn't matter if Rose is "truly sorry" or if he confesses, etc.
What's really a damn shame is that Rose is stealing the thunder from Paul Molitor and Dennis Eckersley, whose accomplishments we should be celebrating today.