The DH rule for pitchers was proposed at least as far back as the 1930s. It wasn't too far into the lively ball era before observers noticed that there literally was no floor for how badly a pitcher could swing a bat, as long as he could pitch effectively. By contrast, nobody who bats .100 keeps a job as catcher very long. By now of course a lot of factors have intervened which make it tough to break down. But, I took a look at catchers and pitchers (at least 85% of their games at those respective positions) with at least 50 plate appearances in 2019, and ranked them by OPS. There were quite a few stinkers among the 75 catchers who made this threshold of use - 6 guys had OPS below .500 (MLB average was .758), and Anthony Benboom (Rays/Angels) brought up the rear with an OPS of .349 built on a mighty BA of .150 across 54 plate appearances. Think that's bad? Of the 41 pitchers who came to the plate 50+ times, 20 of them had worse OPS than even Benboom. At the top end, Zack Greinke and Steven Brault were good hitters, but at #3 was German Marquez with an OPS of .583. Management has to weigh the value of the catcher's mitt versus the bat, and only a relative handful of glove-only guys get much playing time. By contrast, there's no strategic weighing of bat versus pitching arm going on by NL team management, at all. (And catcher is indeed the only position where such ineptitude is even countenanced - second base had a low OPS of .480, shortstop .487, and I didn't bother to check the other positions further along the spectrum.*) I think it's purely a strawman to mock the DH by suggesting every position be subbed for. The DH addresses a specific imbalance in the game, one that was recognized for decades - not just a lunkheaded desire for "moar offense!!1!". * "But but but... Zack Cozart!" Yeah. Zack Cozart. Him and three others.