Disclaimer: Choosing to reply here for "reasons" but there's lots of siblings I could've chosen.
Reading comments so far and the article I think we're mixing up many different use cases and choices.
If I set my browser to English, that means I want the interface language to definitely be English. Do no serve me the interface in Japanese just because I'm in Japan. I won't even be able to find the "Change language here" dropdown ...
Now search results are a different thing. If I type something into www.google.com while being on US soil with en-us as my language setting that is in French, isn't it obvious that I might primarily be served French language content and that is what I want too? While the interface of Google is still in English? Or vice versa? If I type an English language query into www.google.fr while fr-fr is my language setting, I expect worldwide results in English, while my interface is still in French. Sure, restaurant name search results I might want sorted differently based on location and that's a good thing overall, but leave my interface language alone!
Reading comments so far and the article I think we're mixing up many different use cases and choices.
If I set my browser to English, that means I want the interface language to definitely be English. Do no serve me the interface in Japanese just because I'm in Japan. I won't even be able to find the "Change language here" dropdown ...
Now search results are a different thing. If I type something into www.google.com while being on US soil with en-us as my language setting that is in French, isn't it obvious that I might primarily be served French language content and that is what I want too? While the interface of Google is still in English? Or vice versa? If I type an English language query into www.google.fr while fr-fr is my language setting, I expect worldwide results in English, while my interface is still in French. Sure, restaurant name search results I might want sorted differently based on location and that's a good thing overall, but leave my interface language alone!