Well, if the ai is targeting the inhibitors first than he would still waste time cos he needs to destroy it + run away to the edge of the gravity well.
Yeah, but would you rather have the AI actually DOING something that you can react to instead of it just sitting there while it waits to jump out?
And depending on how many ships it has in the fleet, it might succeed in destroying the PJI in less time than it would take to jump out with the PJI active.