I'm based in Chicago and got the same email ascribed to NYC. (Didn't check the signature however - presumably a Chicago manager)
I'm less disturbed by this than others, because I have always tipped -- my trips are usually 25 miles or more (home to/from airport) and the savings over taxi so great that it was always a "share the savings" impulse...even with the ORD/MDW surcharge and a small tip, I'm saving significantly over regular cab fare. That model might not apply in other cities.