I was taught that, linguistically speaking, people do not learn a second language if one suffices, just as people do not become ambidextrous as long as they have the use of their dominant hand. English suffices throughout the world.

Weil sie denken, sie müssten keine Fremdsprache lernen, da genug Leute weltweit Englisch beherrschen. Vermute ich mal^^ I guess it's because they think, they needn't learn a foreign language, cuz enough people worldwide speak english.

Most people in the world are monolingual. So they've learned a language, but can barely speak it. That doesn't make them bilingual. There are thousands of Brits that know some French, a large number that know some German, too. I think you'll find the Americans are the thick bunch. LOL.

That's a very big generalisation

I think for any educated person seeks to have any other knowledge of the culture because humans are curious by nature