Why didn't Yelp early on see that they could become OpenTable, or GroupOn? In China, services like Dianping combine all three plus mobile payments: Restaurant reviews, booking, discounts, and payment, and even delivery services.
Surely Yelp could have seen how other crowd sourced content farms became commodities? Yelp is trying to blame their problems on Search, but the real problem to me is that they failed to adapt their business model in the face of a sea change in computing and from mounting pressure from competitors like TripAdvisor.
The Yelp CEO seems to be indulging in the classic approach when your business model fails to resort to patent lawsuits, copyright lawsuits, or begging anti-trust regulators for regulatory capture.