The thing is they are copying gameplay and graphics style. All the assets and code are made by Zynga(hopefully). And I don't think it can be proven that their games are actually being advertised and misrepresented as other products.
http://kotaku.com/5931661/ea-sues-zynga-says-the-ville-rips-off-the-sims
By calling Zynga out on this illegal practice, we hope to have a secondary effect of protecting the rights of other creative studios who don't have the resources to protect themselves.
I don't believe this. I think this is about money and competing products. I think if given a favorable ruling EA and other large-resource organizations will squeeze successful competitors.
It has been tried in the past.
http://en.wikipedia.org/wiki/Fighter's_History