You're exactly why they don't... many of you speak English, so why would they learn one of the most difficult languages in the world beyond basic phrasing?

I've been all through Asian (never lived there but spent weeks at a time in numerous countries) and I've never once ran into a language barrier because I don't speak one of the Asian languages.

Asia has approximately 800 million English speakers, which in effect means it has far more English speakers than the entire Anglosphere.

Approximately 2 billion of the total global population of 7 billion can communicate in English.

Asia has almost half of the English speakers in the world. Why would an expat spend their valuable time learning a language that they will rarely ever absolutely need?

Asians learn English because they have to, not because they want to, that's the international business and travel language.