> however it just so happens that English is the de facto international business language and the world's most widely spoken language.
Purely on the basis of experience, I must disagree with you there. As someone who does business internationally, I use four to five languages in the course of my professional day-to-day, plus one or two other languages socially.
If you are a monolingual English speaker, you will be at a terrible disadvantage against most of the world, and in particular against every recent graduate of a European university, who will have studied a minimum of two foreign languages, plus whatever their local language(s), plus whatever their own / family / social language(s) may be.
You may find it idiotic having to learn, let's say Norwegian, to do business there, but when your Norwegian speaking Belgian competitor¹ gets that multi-million dollar contract after taking the local client out for beers and a social chat in *their* language, let's see how much of a consolation is going to be the argument that "English is the language of business".
¹ True story, more or less.