In most jurisdictions, it is still illegal to put a baby or very small child in the passenger seat. I can't speak for anyone else, but in my own case, I think the risk of forgetting to turn it off when a child is riding in the front seat is going to be much higher than the risk of forgetting my child in the rear seat.
That's really the calculus: How is it that we think we could forget that our child is in the back seat, but remember to disengage the air bag every time we put their seat in the front?
Admittedly, CA is one of the states where it is a regulation, and there are a decent number of people on HN from CA.
Putting kids in the front seat only works for one kid, only if there’s one adult, and only if the front airbag can be disabled.