[kaoD]

> The single-event-thread design is not without its own problem; programmers have difficulty in understanding and abiding to it too.

Definitely not my experience. jQuery is very popular among unskilled programmers because its async model is very easy to understand. I use it to teach async!

> That problem cannot be reduced by some API or language trick.

Why? Reducing problem by API or language tricks is exactly what abstraction is for.