Not surprised by this at all, unfortunately. The moment Tapia was acquired you knew he was going to play too much.
The best lineup is Kirk and Jansen at DH and catcher. When one catches, the other DH's. It sucks that the position player depth is so bad that the two catchers playing at the same time is the optimal lineup, but it is what it is. Yet, Jansen comes back, and Buntoyo refuses to play that lineup. I think he's done it once since Jansen came back. He's still giving DH opportunities to Collins based on like a 5 day hot streak in April that inflated his numbers. He has a 20 wRC+ in his last 48 PA's, which accounts for 70% of his PA's on the season.
As much as I can't stand Charlie, I think the blame has to be shared with the front office. The depth on this team sucks, and if you load the bench with scrubs and hand that roster off to a minor league manager who wants to play everybody, then you kind of deserve what you get.