The plane isn't a 500mph missile at that point, and law enforcement still have easy access. It's not overly difficult to handle APU and engine startup on a mod

The plane isn't a 500mph missile at that point, and law enforcement still have easy access. It's not overly difficult to handle APU and engine startup on a modern plane, but there's still a bunch of other obstacles to overcome, wheel chocks, etc. And you're presumably not going to have a compliant tug to push you back (you can technically push back yourself with reverse thrust, but that's a whole thing unto itself).