I too believe that young people are just self-conscious, perhaps because they're not used to speaking it.

A lot of old people dislike foreigners to a certain extend, however, and I bet some of them wouldn't speak it on purpose even if they could. For instance, an old lady at a drugstore complained to the cashier at the register because I took too long picking some medicine, while "there were Poles waiting in line".

Let's just say that Berlin was more foreign-friendly in my experience.