Because they are super nice. Out of all the trips I've done, I've discovered that I enjoy foreign people the most. At least the ones who understand English. My first ever Pax was Australian. Very talkative couple (he was with his girlfriend) and it was a great way to begin Ubering. Not to mention a $3 tip for a $3 trip after Uber fees. Today I had someone (I think she was from Asia or somewhere like that) and right as I picked her up, I knew she was someone that would be talkative. We laughed and talked about how bad a person's driving in front of us was, and she joked how afraid she was to cross the street so she just decided to Uber. She didn't even mind that I had to go down a little ways to make a Uturn. That said, I prefer foreign people. They just seem more friendly and grateful.