Baseball just has to accept what it is. It's not a mainstream game (anymore). It's a regional game. Fans of baseball will watch their team's games, but "casual fans" will not regardless of arbitrary changes. MLB is better off trying to better market their stars, and even then, it probably won't mean much.
It's f***ing stupid to think that shaving 8 games from the schedule, shortening each game by 20 minutes, limiting bullpen changes, etc, is going to mean a damn thing as far as getting more fans to watch. It's stupid and naive. How about replacing home plate umpires so that balls and strikes are called more accurately? How about putting the DH in the NL so we don't have to see .100 hitters batting in the 9th spot every game in one league, while the other league has an actual hitter in place of that? There are things that can make the quality of play better. That's what they should be focusing on. Not trying to make a intrinsically long/boring game shorter by a meaningless amount of minutes.
Baseball makes money the way they are now. TV ratings are down for everything. Just embrace what you are. It will be a concern many years from now when the older demo dies out and they'll need to get new fans, but I think that will happen regardless. It won't lead to monster TV ratings, but it doesn't have to.