..NET makes Catalyst Control Center extensible, so tweak utility authors like
Rage3D can write a "plug-in" that integrates into the main control program
with relative ease. Plus, .NET is a buzzword, so CCC acts as a checkbox
feature for OEM appeal.
Just use the regular Control Panel version of the drivers if all this seems
like a load of BS. Remember, you have a choice. Exercise that choice before
it gets taken away...