The scholarships quote is not applicable in this situation. In the mind of Twins coaches, he is a good fit for the third catcher role. He plays excellent defense, he has a good rapport with the pitchers and nothing is hurt by his sporadic playing time. The problem with using anybody with any kind of upside in that role is that he'll have a hard time ever reaching that upside while getting a handful of at-bats per week. Any player with legitimate ability might object to the unglamorous nature of the role but Butera knows it's a miracle he has a major-league job so he keeps happily plugging away and working his ass off.
Personally I wouldn't give a roster spot to a guy with as little offensive ability as Butera and I probably wouldn't even carry a third catcher (though with Mauer and Doumit leading the depth chart I can see the wisdom). But it's not the most indefensible thing I've ever seen. I'm really tired of seeing it constantly regurgitated as some proof positive that everyone running the Twins is an idiot. At the end of the day Butera has very little impact on the success of this team one way or another.