Any thoughts on why Asia yet to be unionised?

They are. Japan first. That caused a collapse of all production of most things they made because foreign owners of companies there didn't want to pay a living wage...so most of Japan's production moved to China. China then got a Middle Class and wanted unions......so production of a great deal of foreign products made in China moved to Vietnam and India.

they are busy

It's a big place.
East Asia, South Asia, Middle East, Central Asia might make more sense as units.
But there's a lot of history in all of that

Why did I read this as "Un-ionised"???

It's so much bigger than Europe, and a lot of the Asian countries are authoritarian.

They don't play that game.

Divide and rule by the UN sponsored by UK & USA