I really don't want to support stereotypes, but my girlfriend works on the bus station and in her experience of more than 2 years the french are the toughest customers to deal with. They refuse to learn even a handful of basic english expressions. She also tries german or spanish, although she is not exactly fluent in either. So most of the time, they speak french to her and she responds in croatian, waiting for them to give up.

I see your point, but nowadays English is not merely yet another foreign language, in a way it belongs to people of all over the world by right of their contribution to universal English-speaking culture (think Vladimir Nabokov or Linus Torvalds). Today Runglish (flavour of English spoken by those whose mother tongue is Russian) is nothing but derogatory term, but some day, when most of Russians will know English well enough, we are going to start to skip articles out of pure pride.

> I wonder how widespread this "X is my native tongue, so I'm going to speak English in a strong X accent, because otherwise I'd be submerging my identity" attitude is?

I hope you understand that hiding own accent is not the easiest thing and requires some effort even after lots of training. Our vocal apparatus is adapted to our mother tongue, so even if we are capable of speaking all English phonemes, not all of them are "natural" for us.

Yes, but the anecdote I wrote about was a situation where someone was deliberately not making any effort to improve their accent. It wasn't about trying but failing.