Just to clarify a few points. The hitter who was called out was in the box the entire time. He was tapping his bat on home plate and was not looking at the P at the 8 second mark and that was deemed a rules violation. IMHO once the season begins umps will use more discretion. For example, it has been said that if a hitter gets some dirt in his eye, for example, the ump will not enforce the rule.
I like the pitch clock rule because pitchers and teams have needlessly prolonged games. Those who view this rule as "new" are incorrect IMHO. There has always been a time limit within which a P must deliver. It was just not enforced. Of course this rule is new in the sense that now there is a clock and the hitter also must be ready to hit. And this is the part of the rule that I don't understand. Why mandate that the hitter is in the box and "alert to the pitcher" at the 8 second mark? I think it would be easier to simply have the umpire signal the ball in play (or never signal it out of play after the previous pitch) and if the hitter is ready to hit, fine, if he is not, that's his problem. I don't understand the logic behind penalizing the hitter when there should be nothing preventing the P from delivering the pitch regardless of whether the batter is ready.
But again, IMHO, once the season begins umpires will use discretion and will only penalize the hitter if he is involved in some sort of gamesmanship. Finally, if you look at the replay of the Atlanta player who was called out, he was really oblivious to the rule as was not even remotely ready to hit. It's as if he was unaware of the rule.