The unfortunate truth is that approach does work, sometimes. It's really easy and common for capable engineers to think their way out of doing something because of all the different things they can think about it.

Sometimes, an unreasonable dumbass whose only authority comes from corporate heirarchy is needed to mandate the engineers start chipping away at the tasks. If they weren't a dumbass, they'd know the unreasonable thing they're mandating, and if they weren't unreasonable, they wouldn't mandate the someone does it.

I am an an engineer. "Sometimes" could be swapped for "rarely" above, but the point still stands: as much frustration as I have towards those people, they do occasionally lead to the impossible being delivered. But then again, a stopped clock -> twice a day etc.