I'm guessing you don't believe in games at all...? I think this would be more of a discussion about whether games are a good thing at all, but that would probably be mostly opinions.
I think games have incredible (and untapped!) value, but I don't think Zynga makes games. I think Zynga exploits game mechanics to make products out of people.
Obvious example: http://www.bogost.com/blog/cow_clicker_1.shtml