I've seen people sucked into WoW, WoW is evil.
I've seen people sucked into Final Fantasy, heck... every RPG is probably evil.
Actually, it seems like any form of entertainment can be rather addictive, the world would be better if that whole industry went away.
You're right, this is easy.
If it is AND if you actually played a game like FarmVille and got addicted despite being very intelligent, despite being aware of how inane the "game" is and how it cynically taps into some primitive part of your brain, you'd realize that your examples are to FarmVille what selling donuts are to dealing crack/meth/heroin.
An extremely important distinction that @saraid216 and perhaps you may have failed to make: The claim is not that X itself is immoral or using/playing X is immoral, but that the intentions and methods of the dealers/creators of X are.