The check backseat is annoying - but it's also easily disabled through the main screen, which makes me think it's not a regulation, unlike the stop/start re-engaging every start so that it's not a defeat device.Actually the backup camera was due to people backing up things/other people in the dead spot you have from a rearview mirror.
There was a case where a person backed up over their daughter/sister in the driveway because she was so close the door that they couldn't see them when they backed out (I think they where laying in the sun or something like that). I think this was one of a few cases that mandated backup cameras.
The check backseat thing is incredibly stupid, but there was a case locally where a baby died from someone not checking. I'm sure adding a reminder to the dash when you shut the car off didn't cost that much.
Shit happens-if it saves someone's life its worth it.