Completely agree with Tarn. I would go further, and describe certain types of games as evil. Social games, in particular, I believe have evil game design.
It's a view I've often come across on indie game-related blogs.
Companies like Zynga help push the issue to the fore-front: They get continuous real time data about how changes in their games effect player behavior, and try to use that to maximize the addictive factor.
Here's an interview with the somewhat controversial but always interesting game designer Jonathan Blow: http://www.pcgamer.com/2011/02/15/jonathan-blow-interview-so...
In the second half, he talks about social game design. I'm very much with him on this.