To play devils advocate, the batter also wants to know the pitcher has control of the ball. It has always been an unspoken rule that pitchers did this in colder

To play devils advocate, the batter also wants to know the pitcher has control of the ball. It has always been an unspoken rule that pitchers did this in colder weather, because the ball is harder to grip in cold weather. A batter would prefer to know the pitcher won’t unintentionally hit them with a 96 mph fastball. I will completely agree this has gone too far. There are a lot of unspoken rules in baseball which to me is a feature not a bug. This has gone too far, but there are more layers than just “this is against the rules”