But ORS, the formula is just a mechanism to convert from total AB's into the actual data you're measuring. You could get the data differently, by actually counting each at bat that the ball was put in play. If you did that you would obviously not count strikeouts. But since you already have the AB's and K's being measured the formula is just a shortcut.
I have to agree with User Name, strikeouts have no effect on BABIP. They just reduce the sample size.