This is a meme that comes up again and again.
At one time I was moderately competent in French and so was comfortable going up to counters and just asking questions in French without hesitation, in both France and Belgium.
That's to say, I've a lot of experience with this as a foreigner. I've had everything from beaming smiles and responses in French, to confused expressions upon which I've repeated myself more slowly, to grimaces and reluctant replies, to just outright replies in English.
The truth is, the regularity with which you're treated rudely is about the same as anywhere. Sometimes you go to counters, or restaurants, or bars at home and are treated very rudely. The person working there might be genuinely miserable, they might have just spoken to another customer who was rude, they might just be tired. You don't take any of these things to mean anything about the culture where you live. It's just people.
Any type of broad summary of 'the people in X' is always something I take with a massive grain of salt. You hear it all the time. Somebody spent 3 days in Hanoi, and had a friendly interaction with one or two locals, so the Vietnamese are lovely people, while in Hong Kong they had a rude taxi driver, and had a hotel on a busy road, so the people there are a bit ruder, a bit more rushed and loud, they say. Whilst the Australian they met who bought them a beer.. such generous people, those Australians! You get the idea :-)
