And, why would they want to really? Learning a language is a daunting task. Yeah, you can do it, but its more than just learning words. Its about discovering a whole new culture, and that takes a lot of energy.
Its a complex issue. We all have our daily lives. Good things and bad things happens to our culture, associates, friends, family everyday. Its hard for a person to want to take on any more challenges.
On my end, I am learning Korean. Partly because they are a big focus point of (potential) conflict to our culture. Partly because I want to watch Korean Dramas without reading sub-titles. I'm about 7 weeks in, and I feel drained trying to learn the language. Still gonna power through for the greater good.
TLDR; The world could be a better place, especially from learning another culture. I'm learning Korean currently. Its hard, but I want to really know more about them.
Most other don't have the time because ... well, umm.. "have you seen the latest Bitcoin price!!!??"