> No argument there. But it's pointless if you are IO bound.
Why would you just accept "we're IO bound, nothing we can do"? I'd do everything in my power to make my app go from IO bound to CPU bound -- whether by optimizing my code or buying more hardware. I can tell you if our OLTP servers were IO bound, it would run like crap. Instead of < 1 sec, we'd be looking at 5-10 seconds per "user transaction" and our users would be screaming bloody murder.
In theory, you can always convert your IO bound DB to CPU bound by stuffing more and more RAM into your server. (Or partitioning the DB across multiple servers.) Whether it's cost effective depends on the DB and how much your users are paying you -- and that's a case-by-case analysis. Not a global statement of "IO-bound, pointless".
We all want our systems to be CPU bound, but it's not always possible. Remember, he is managing a 5 TB Databse. That's quite a bit different than a 100 GB or even 500 GB database.