That might work for intact CubeSats and bigger objects, but good luck catching the shrapnel sized debris with nets. Unfortunately bigger objects will tend over time to break down into smaller chunks due to collisions, chunks which will over time create even more small debris.
We need to put in orbit an asteroid made of ballistic gel into which all this hypervelocity buckshot can go bury itself! Let it turn in different orbits until they are cleaned, then let it drop back to earth, despite its size it will burn up easily.
(Shucks, no mad scientist icon)