I think it puts the National League at a disadvantage come playoffs - aging good hitters more willing to sign with American League teams knowing they can get more days off or be the full-time DH eventually. Guys like Nelson Cruz, Giancarlo Stanton, JD Martinez of today are elite hitters who you might not see hit as much without the DH position (not to mention past guys like David Ortiz, Jim Thome, Paul Molitor, etc.) Tougher on NL pitcher because they become accustomed to pitching around the pitcher's at-bat or a lesser bench player. Throwing a pitcher to hit every 9 at bats makes it easy to pitch around the batter before, then pitch to the pitcher and the batter after the pitcher (usually leadoff) usually is not going to have the benefit of a good hitter behind him - so a 3rd of the lineup is made worse because of that one pitcher hitting. Dumb stuff like pitchers getting injured with a HBP or getting injured on base paths (happened to Max Fried in the season). AL pitchers probably love pitching in NL parks because it's a little easier for them without as tough of a lineup.