It’s no secret that missing bats is important for pitchers. Last season hitters hit .255 with a .426 slugging, and in at bats not ending in a strikeout, hitters hit .336 with a .562 slugging. It’s vital for pitchers to miss bats, it’s the only way to (essentially) guarantee an out. Contact forces additional parts in order for an out to made, a fielder moving, fielding the ball, throwing, and finally throwing it to another player.
To try to prevent a runner from reaching base, the best way is to miss bats and get a strikeout. But it’s important to do it on a plate appearance basis and not a per nine basis.