Yes, I'm serious. The whole idea is to increase runs. Of course, no one likes the idea. If you think about it, that's how games are played at the very low level of baseball. Little League, pony league, etc. You let the pitcher stay in the entire nine innings. You don't rotate the pitcher out a billion times to close out the final innings. The might get relieved once. Rarely twice in a game.
Another way to change the game and to speed up the game is to have a pitching clock, like a basketball shot clock. Unlike football and basketball and hockey, you can't just be standing around for a very long time. In baseball, the pitcher can take his grand old time to throw a pitch, making sure the first base runner is not going to steal, disagree with the catcher's pitching selection, talk it out with the pitcher on the mound, talk it out with the coach, etc. If he is forced to throw it in a certain amount of time, his body is going to get tired faster.