Nimblebit team is 3 people, Zynga is 2,800 strong. There's a disadvantage that makes the ripoff harder to fight.

Plus, Zynga sues when they think they get copied (http://techcrunch.com/2011/06/16/war-zynga-sues-the-hell-out...). There's a good chance that Nimblebit won't have enough money to fight back.