I agree that buyers should have the option to purchase simpler cars. But I think backup cameras are too valuable of a safety improvement to leave out. About a year ago I saw a toddler very likely saved by the backup camera and proximity sensor. This is of course just anecdotal, but it sold me.
Yeah, I guess then you don't need a screen for display. And to be honest the proximity sensor may have had the greater effect in the situation I referenced. I could hear it beeping from where I was about 30 feet from the car.