The ionosphere would quickly recover. But they wanted communication unaffected by disturbances, and that is a role for satellites.
Ahh, another example of Earth healing itself no matter what mankind inflicts upon it. Someone get on the jungle drum and inform the greenie weenies.
A fortune will be had for the person or group who make an efficient means to clean up all the orbital junk. Right now there's a whole team of people (at NORAD?) who have to track it all.