In my case, my parents and most parents of my colleagues strived to give us opportunities to learn English. They knew that with ability to use it, we would get better jobs, salaries and a chance to travel the world. They viewed it as investment in our future.

And boy, were they right. Those who didn't learn, even if they are specialists in their respective fields, are fairly limited with jobs they can take and have much harder time getting more advanced knowledge of their profession, since huge chunk of top academic books is written in English.

That's the long story short pretty much. English is a significant language in the world right now, not sure if not even dominating. If your country's language has limited "range", you are kind of dependent on learning a more wide spread one to be able to communicate worldwide.