One of the top comments on that page is that they loved the tone of article. Personally I hate sarcastic responses (no matter how correct you are), which sound very unprofessional. I hope to see less of these types of responses in the future.
Why do you expect them to be professional? Obviously, the response was in jest and wasn't some formal response by FB's PR group. This was just done by a couple FB workers who laughed at Princeton's methodology. To expect a certain level of professionalism for someone's FB post seems a bit absurd and pedantic.
I also hate sarcastic responses, america, and cake.