As a general answer, hitting's very important, even in a catcher
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But like everything else, it will depend on the program and the coach which kind of catcher is chosen. How much offense does he have on the rest of the team? What's the pitching like --- a catcher who can't block up for some staffs could mean a merry-go-round on the bases, for example. Is it a small ball, running conference or an arm-and-hammer one?
I remember some years back when the Astros brought back Ausmus after a bout with a "power catcher"...they finally figured out their young pitching staff was going south fast without the support of a quality D guy.
It's hard for me not to be a bit bitter on this question. My son is the type of catcher that makes the pitching staff better and will shut down the running game. So he's playing behind a hitter who can 'catch'. And watching his career go down the tubes while seeing runs score on PBs and two-hoppers to second....well, other than the ones that sail into the OF. Where's Leo Durocher when we need him --- 'don't like them guys who drive in two runs and let in three'.
Taking a guy who can hit and developing his defensive skills is a nice idea and may even work with some guys. But catchers are a different breed. They have to have the desire to be beaten up back there and have the instincts to read the batters and baserunners. Then there's the technical observation, patience, and psychological skills to handle pitchers. Not all of what makes a quality catcher comes from reps.
Futurecatcher is right, coaches don't have any idea how demanding the job is.