A game that markets itself through a social network is not intrinsically social. It's just parasitic. Zynga is Facebook's tapeworm. Games, for over 5000 years, have been a lot more social than Fartville. This Zynga shit is alienating. It's about as "social" as playing the lottery is intellectual because it involves numbers.
I was at Google during the Real Games battle, and inadvertently became somewhat of a lightning rod for it. I'll skip over the whole history but just say this: if decisions had been made on merit rather than rank, Google+ Games could have been something, and if it had, Google+ would have become an actual contender in the social space. I saw first-hand the damage that Zyngaism can do to a potentially major product.
I think all of this Zyngarbage is an attempt to emulate the success of Magic: the Gathering and its iterative pay-to-keep-current mechanism, but without the insight and work that made Magic (in spite of its annoying pricing model) great.
There will be a flight-to-quality in the gaming space (Zyngarbage will always exist, just as third-rate porn always will, but it will become a low-margin commodity) but I have no idea when it will be and what it will do to the current cottage industry.