His defense is good, but not otherworldly as we thought it could have been. If his glove stays at "solid but not spectacular," his bat won't play. Frankly, I thought his glove was a little underwhelming, if not straight up disappointing, last year.
If his glove was outstanding last year, maybe they would have had more of a reason to move Swihart to a new position. I think that since CV didn't make any great leaps last year, that they think Swihart's upside may be worth keeping at C. They obviously don't see CV as their future at this point.