OK maybe things have changed in recent years. I was always annoyed when coming to visit family living in Berlin for a couple days or driving in to a conference, and inevitably there would come a time when I would have to ask someone for help and I would have to ask in English because I do not speak German (although due to youthful immersion I start to remember it again after a couple of weeks) and they would inevitably answer in German.
I could somewhat understand when we stopped in a park asking where the convention center was of just a couple people by the side of the road, but asking a ticket agent at a train station what route I should take to get to a particular station and getting replies in German seemed especially rude.
At any rate despite some good experiences with Germans regarding helpfulness I have had a few too many negative experiences.