Making ATR everywhere, or more prevalent has been suggested before, but I think that would be a bit excessive. We need to keep in mind that ATR also goes after PvE players, if they've been bad, and there have been complaints about them in the past, same with notoriety.
What I wouldn't mind so much, would be Spec-Ops, or Wing assassination level police in high security systems, instead of some total pushover cops that you can basically ignore. Those enemies actually have the ability to do some hurt without having station level lasers.
Still, at the end of the day, to keep something like a shieldless T9 from exploding, the response from ATR would have to be instantaneous. Like immediately hostile on drop, 100% instant, because no amount of NPC, or even Human police can overcome a poorly built ship that dies in one volley.