But it's not just that: to black start the grid you have to shed load - that is, you need to trip all the breakers along the grid, and then very carefully restore loads to avoid knocking yourself offline again.

You just plain aren't going to do that in an hour when you're offline because someone trashed your automated systems - resetting and restoring the grid would require people on site, in communication. That's not happening in an hour without staggering expense.