That looks like they are anticipating driver behavior that isn't there. A driver does not want to look for an outlet in the next town and be forced to drink a Starbucks until topped off because there's nothing else to do. IMHO the goal of hybrids should be that they can run mostly on batteries once the car gets into stop-and-go city traffic. And with the battery at 30% that's not going to happen.
Maybe they should spend some more time talking to Prius drivers? Even if their unions would bristle at the thought ... :-)