[kaoD]

> the computer is of course async in nature; but the abstraction on the app layer does not have to be.

Aren't computers actually synchronous? The abstraction on the OS layer is what makes computers async.

At the programming-language layer, async means you can write programs based on how the user and your program interact with each other. Other applications (and the OS itself) behave asynchronously too. Why make it harder?

Of course it shouldn't have to be that way (it didn't use to be), but it's very convenient to think around "what is actually happening" instead of "what the synchronous execution of the program is doing".

EDIT: but now I've seen you only meant a specific subset of async. I'm leaving the comment here anyways.