Mark Twain or Shakespeare I'm sure has some quote about the inversely proportional relationship between self-proclaimed worth vs. externally validated worth, but I've noticed an increase in the amount of YC promotion as the value of the YC brand begins to ebb (airbnb trolling by NYC, zenefits and whatnot).
I don't think YC's brand has been criticized much more than it has in the past. I think the Thiel drama is the worst they've had to deal with in the past year or two.