I think the reasoning behind the changes was to speed up the game. There is a continuing trend of lost viewership. That's means less revenue and has their complete attention. It might not be due to the ever increasing length of the game but that was their first line of attack. Trying to compensate for the extra time for reviews, which will never be removed, required shaving time somewhere. So, eliminate the pitcher / batter tango by putting a time on the antics seemed a good place to start. I can't say I'm in love with the change but I don't miss the cat and mouse game that goes on at ever at bat.
As a huge fan of the game the boys play... I'd limit the amount of pitcher changes... or decrease the number of relievers.. or bull pin size. That takes a lot of game time and with less pitchers there would be more offense. They have already implemented rules limiting mound visits which I like.
There really isn't much more they can do to the game to speed it up if that's the reason for lost viewers. The reviews take a lot of time and they are boring for the viewer. Now that they have it, I can't see them taking it out of the game. They have limited teams to the number of reviews they can request but the process is too slow. Speed that up could shave a few minutes.
The bottom line to me, is the game too long, or is it just not as exciting to today's fans? I'm not totally convinced it's a time thing. We live in a lot faster world than we did 50 years ago. I do think it takes a baseball fan to be entertained by the game and the time it takes to watch it. I do think speeding it up some is okay. What the game really needs is more action to draw in new viewers. I can think of ways to make it more exciting... action packed... but not without completely changing the game we know.
The clock changed the game and I can live with it. They change it much more and baseball will no longer be baseball.