I think killwhoring happens because Nod often doesn't have a good way of finishing off a crippled GDI base short of a mass Tick Tank rush. Whereas with GDI it's a simple matter to just get a Titan or Disruptor and then driving over to Nod base to pound it to rubble, Nod vehicles aren't anywhere as efficient at demolishing base structures...and they have much thinner armor to boot, making them vulnerable to being whittled down by Officers and Jumpjets, or bombed to death by Disk Throwers. So, if your team isn't coordinating a mass Tick rush, what's a Nod player to do? Get a Stealth Tank, Buggy, Devil's Tongue, or Reaper, and try to kill enough of those Officers and Disk Throwers until GDI runs out of money. Hence...killwhoring.