pff, please, His overall numbers are a .771 OPS at the moment (.240/.320/.452), which is well above average from the catching position, and is in fact above average for hitters in general. You get .450 slugging and average OBP from the catching position you're doing well. His glove and arm are both average, neither an asset nor a liability. Taken as a whole the guy is pretty much replicating what you could have expected from Varitek in an average year, at least in terms of the numbers, and that's with a month and a half uberslump thrown in. He'd have to really tail off before he's in any way a spare part.
Also, I suppose using the same logic that people use to defend Crawford, to back up a guy who's indisputably been worth the investment so far, is so evil.
I don't think Salty will ever be where Tek was defensively, but he's got the upside to reach heights of offense Varitek couldn't touch, and he's already a better defender than VMart. This kid could easily be a star for us.