I understand the overall point of the article is about memory blocking cpu; but the author uses the idea of instruction through-put instruction-memory/cycle a w

I understand the overall point of the article is about memory blocking cpu; but the author uses the idea of instruction through-put instruction-memory/cycle a way to show that the throughput isn't enough just to execute code. So in order to make that argument, you'd have to look at the instruction through-put without the assumption of memory accesses slowing you down. Otherwise the point comparing cpu speed vs memory speed is moot, if you start with the assumption that cpu speed is bound by memory speed to begin with.