YES, IT'S A BAD IDEA
"They don't admit that it's a bad idea because it isn't a bad idea - it maximises the amount of screen space that your app has with the existing hardware"
Funny, my Galaxy doesn't need to cripple the screen so the hardware can keep up. "Maximizing screen space" means using ALL of it, not leaving some dead.
Apple never admits error, why would they back off on this one? "Notch" is Newspeak for Dead Zone, and it exists solely to pretend the screen is a given length, when it's really only as long as the center under the Dead Zone. Neither function nor user experience is improved by it.
Would you buy a television with a big black dead zone poking in at the top? I seriously doubt it.