Maybe my memory is bad but when Castro wasn't geeting meaningless hits he was striking out looking or hitting grounders to 2nd base.
While I am sure the stats are out there somewhere, I have not been able to find anything that details meaningless hits, indicates a K looking percentage, or delineates hitting grounders into the shift. Therefore, I cannot speak intelligently about your memory. I can state, unequivocally, that if you enjoyed watching him strike out in his previous stint with the Astros, you are going to be absolutely ecstatic with him this time, since he has increased his K rate roughly 8% since then. The reality is that neither of these guys is going to strike fear in the opponents with their offensive prowess, but they are still above average defenders. Maldonado moreso. Since the front office has chosen to sign these guys, it is my assumption that they have decided to prioritize defense from their catchers.