He's genuinely been a plus defensive catcher with his arm this year, but he has had a reputation for not calling games well since he first came up to the majors. Either way, I don't think it had as big an impact on this particular game as Ray and Bob's rants would have you believe. The defense was positioned really badly though.
And it's the catcher's job to not call every freaking pitch to LHBs away when he sees the defense shifted for the pull. Either call the manager out to the mound to change it or call pitches that don't intentionally nullify the defensive setup. No excuse for Sludge tonight.