Remote start

The remote start that I have on my 2013 Expedition stinks. It works great in starting it up, but the fact that it shuts off when you open the door makes no sense. First of all the vehicle locks when you use remote start so there is no chance of someone stealing. Second I know the technology exsists to keep the vehicle running after opening the door. I had remote start put on my 2006 Sienna by Best Buy. The system allowed the van to stay on even after I opened the door and would shut down if I didn't put my key in the ignition and turn it to the on position. There was no way someone could steal my van. I know this for a fact because once I forgot to put the key in and when I stepped on the brake to shift into reverse, it shut down.  I'm not sure the reason for the one Ford has to shut the vehicle down once the door it opened. Please change this for the 2015 vehicles.