Why? What difference would it make to game play?
On the maps with lots of overlapping radar coverage the dead radar ring can cover up enemy contacts, for one. For another, it increases the likelihood that someone might meet failure instead of knowing exactly where the safety zone is even with a dead radar.
I would also suggest that instead of the base icon flashing that the radar ring should flash in its place, but I know that will just make map resets even easier. I do not have a problem with that either.
