The All-Star Game and Interly Play

The former pirate catcher hit a home run the win and All-Star game. Elias Diaz has been terrible every year of his career until this one. The Texas Rangers were voting in the starting line up, but not one of them got a hit. Why is interly play so important to MLB? It's gotten to the point where as we who lived through baseball before there was interly play, I think we still kind of see it as strange.