I would believe you when you say you give him plenty of slack if you could cite just one example when you stated on talksox that he managed a single game well or even that he made one good decision in one specific game.
I think you are on record as saying MLB home plate umps should do better than 87% correct calls on balls and strikes. The Sox have played 50 games so far. Assuming at least 10 decisions for each game--including lineups, pitching decisions, placement of fielders, baserunning signals, etc, etc--that's 500 decisions so far. But you focus on the 5 ones you don't like and all of which can be defended and ignore the other 99% that apparently were OK.
I admit I'm completely on the other side of this. I give any manager a lot of slack because of their greater experience and access to trends, stats, players stengths/weaknesses, the context of the season, etc. On top of that, I believe a MLB manager has less ability to affect what happens on the field than any NFL coach or NBA coach or even NHL coach in their domains.
On the other hand, I do agree there is a psychological dimension to MLB managing and that managers can indirectly have a positive or negative effect on his players.
Ultimately, however, it boils down to wins and losses. And in the first 50 games this season Cora has been the best manager in MLB.