I think there's a difference between not liking the questions and answering them rudely. I have never responded as the Polish girl did, but I still don't like being asked, and wish people wouldn't. Pkmac, what makes you assume that everyone who doesn't like those questions would respond rudely?
I guess it is all down to what you think is appropriate interaction with a stranger. I dedicated years of my life to learning French, and have travelled and lived in France, but when I hear people speaking it on the bus or in a queue, I never interrupt them to ask where they're from or to practise my French with them. I want to, but I resist because I honestly feel that it's rude to do that. Even for what might be a legitimate reason. But if I met a French person at some sort of social gathering, then it would be something to talk with them about. That's where I draw the line.