I don't think a DH should make the HOF unless he does something tremendous such as break the single season or all time home run record. If you can't throw or field a ball, you're not much of a baseball player.
I can understand that. In addition, I think DHs will always have a hard time getting into the Hall simply because only one of the two leagues uses them.
Edgar Martinez was actually a pretty good defensive third basemen before his injury proneness forced him out of the field. I don't think that necessarily says anything about how much of a baseball player one is. Does it somehow make you a better ballplayer if you do play in the field, but are a below average fielder? Does that help the team more than a good DH?