Attackers shift to a new target on the same net as IP's are null routed, until the entire network has null routed itself which achieves the same result as DDoS'

Attackers shift to a new target on the same net as IP's are null routed, until the entire network has null routed itself which achieves the same result as DDoS'ing the network. So I'm not sure I agree that removing target IP's from your network is a great solution.