I think this has more to do with Towles's development than him being a particular drain on the offense. He simply wasn't ready for the bigs.
Never was. Purpura scoffed at the idea floated to him by sports talk that Towles should come up to the majors in September for a looksee. Then Purpura was fired and somehow the idea of Towles coming up so soon wasn't a bad idea. And then he had a great September and that led to all sorts of stupidity. The media thought that what happened with Pence is not an anomoly, but what can happen to any AA player who is hitting well. As one of them put it "It can't hurt"... just like it wouldn't hurt to bring up Ben Zobrist (to replace the black hole that was Adam Everett) from AA back in the day.
People think that way never considering the one thing that may be the stumbling block: They're not ready for a major league gig.
Pence threw them all for a tissy last year and people went and got all stupid that it was that easy to do... and so Towles was supposed to do the same thing this year, under the tuteldge of Brad Ausmus. Nevermind that what he did was basically in September against other callups and teams playing out the string. It was borderline insanity but someone on the baseball side signed off on it and now look what you have on your hands. The kid should've been in AAA all year long, screw what the media would've said, screw what fans think, do the right thing.
Whatever happened to Ben Zobrist any way?