There is a "puffer" law in Colorado, where it is illegal to leave a car running un-attended unless it is equipped with remote start! Not sure how often this is enforced though.
I installed an aftermarket remote start on my MT vehicle in highschool and I remember there was a procedure where you had to leave the car running (neutral + parking brake), exit the vehicle, lock the doors and then turn off the engine via remote. This keeps you from trying to crank it over in gear the next morning.... If you don't follow that procedure when exiting, you are denied the remote start.
However still, splicing aftermarket systems into factory wiring makes me nervous about reliability issues. There could be no truth to that though.