alt Hacker NewsMy rule is that if you want to settle in the country, you ought to learn the local language and it doesn't really matter how much money you make in my opinion. I got to B2 and passed the test, but ultimately left Germany years ago. I don't intend to go back but I also don't regret learning the language.
I've lived in foreign places for less than 6 months and still bothered to pick up enough language to at least converse on a basic A1 level. Especially in certain regions where people don't speak english well this is almost a requirement for any daily life that is not work related. I can't imagine living somewhere for six whole years without picking up the language at all. Maybe if you actually hate the place and are sure you will leave again after that stint, but the above commenter doesn't seem to fall into this category either.