Full disclosure: I hate the DH. Not just the rule itself, but the clumsy, clunky way it was implemented that nobody ever even bothered to refine. Even apart from its establishment in one major league and not the other, it's weird and arbitrary -- why should pitchers be the one position that is under no expectation to acquit themselves at the plate? It's particularly bizarre since in 1973, the year of its introduction, teams regularly started .220 hitters in the middle infield and at catcher. It's not like pitchers were the sole cause of the anemic offense of the era.
If I had dictatorial power over baseball, I'd scrap the DH entirely, but I think the toothpaste is out of the tube here. Instead, I think we should completely untether the batting lineup from the defense, and have a lineup of nine designated hitters. We should have, essentially, offensive and defensive lines in baseball. Nobody in the batting order is obliged to take the field and vice-versa. There's no doubt there are plenty of players with the athleticism and range to play standout defense, but who never crack the highest level of play because they can't turn around big league fastballs. Why deny them this shot, and ourselves the highlights? Why force some of the biggest offensive stars to sit during interleague or World Series play because they can't be trusted with a glove? Why not have the absolute best players on both sides of the ball?
As long as you're forced to find a position for big bats who have no business in the field, you're not putting the best possible product out there. Having separate offensive and defensive lineups in baseball will not only create about eight new jobs per team, but also prolong players' careers across the board by reducing physical wear and tear.
You'd obviously have a few players, your Mike Trouts and Manny Machados, who would still see action at the plate and in the field, just like Deion Sanders was versatile enough to be a standout corner, punt returner, and wide receiver as needed. But the bottom line is that decoupling the offense and defense will improve the quality of play and give us new players to get excited about who we'd otherwise have never heard of – it might also rekindle interest in baseball among kids whose parents can't necessarily afford bats, batting gloves, helmets and the like but who could spring for a glove.
We've seen specialization fully realized on professional pitching staffs, and managers have always made late-inning defensive switches with the game on the line. It's time to usher this movement toward its rational conclusion and have fully separate offensive and defensive teams in baseball.