I mostly agree with you (not the least of which is that blocking I/O is a damn fine API), but the reason that people use async I/O is to have lots of outstandin

I mostly agree with you (not the least of which is that blocking I/O is a damn fine API), but the reason that people use async I/O is to have lots of outstanding requests. Typically you would use select (or similar) to service whichever one responds first. That way you can multiplex many I/O streams onto a small number of threads. If threads are memory-intensive, you almost certainly have to do this.