Well, the obvious answer is that if you hit a home run, you drive yourself in as well, instead of needing someone else to come up with another hit to score him.
If Mauer had 10 more home runs, and they were all solo home runs, he'd had 95 RBI, and likely a few more and be over 100.
But, I would never advocate him changing anything about his swing or his approach.
Production is production - But you also need to drive in 100+ if you are going to be considered a top run producer in the MLB. Every team needs that guy. Most of the time it comes from a guy who can change the outcome of a game with 1 swing. It's awesome if you can do both, but hitting for average doesn't do anything for your team if you're only one of a few guys getting on base (as it pertains to production). Mauer basically does what Jeter does. Hit for average and be that team leader. Mauer needs some Cano's - Grandison's - Tex - Swisher's - etc. to help with the run production. Or get a ton of players who hit for average and can steal some bases (get in scoring position). Willingham was an awesome pick up and the Twins will benefit more when their young farmhands make it to the show. They have that nice combination of hitters (Arcia / Rosario / etc.) and power Sano / etc.). Twins fans need to just be a little more patient and Joe needs to be just a little more productive. Hit .290 with 20 homers and 100 rbi. - That works