Why no passive alarm set?

[rh71]

If you ever forget to lock your car via remote or comfort access door handles, the alarm never arms. Never, as in never. I understand there can be reasons where you're working on the car inside and outside and you want it to remain off but this can be a pretty bad tradeoff if you ever do forget to set it.

Say you're carrying tons of groceries and you can barely close the door... you do it with your foot and run inside. The car's left out there, unlocked and with no alarm. In my case my wife exits the vehicle after me all the time (she's preggo and slower to get out) and with comfort access she's the one to do it but sometimes forgets - and by then I don't always remember to either. It was left unarmed the entire night but at least it was in my garage in that case.

Even cheap alarm systems set it passively after 30 seconds or so. Did they overlook something here? Why not have it to be on the safe side? Manual does not indicate any passive alarm.