I have to assume that those who passed the ordinance have remote start for their cars so they can warm them up without having the keys in the ignition, the doors unlocked or even go out in the cold to start them.
We don’t all have that luxury, yet cars need to warm up before driving them in cold temps. Are we to sit in them and freeze while waiting?
Problem comes when folks living in a tight, packed in neighborhood do this. Car exhaust can make it into the house next door. Enough to set off a CO detector. As laws go, for urban application, it doesn’t bug me.