Personally, I like that websites explicitly ask me what language I want their content to be displayed in. Even though I am a native Spanish speaker, I find Spanish grammar and syntax unsuitable for technical communication because of its excessive rigidity. It also does not help that the Spanish Royal Academy still believes it has the sacred duty to contain the menace posed by terms and idioms of foreign origin (Anglicisms in particular). Basically, I can choose between using "illegal" Spanish and not saying anything useful at all! In practice, I have switched to English for most of my online interactions, including content consumption. So, at least in my case, "I am a native speaker of language X" does not necessarily mean "I want to consume content in language X".

With respect to asking users what their country is, this has never affected me, as I am not a frequent traveler, and, when I do travel, I only rarely use the Internet. But some people are simultaneously much more frequent travelers than I am, and much heavier Internet users when abroad. I cannot tell what their experiences are, but I guess most of them want to be able to visit the versions of websites associated to their countries or regions of origin/residence.