I think his calculations are off, but his general point is pretty accurate. If you're doing pure CPU mining, even $100k worth of hardware won't generate you that much money per week.
As a pure guess I'm going to assume the actual return you'd see is a few hundred dollars per week.
Depends on the cryptocurrency, he used bitcoin in his follow up to my comment. CPU mining of bitcoin is horrendous (you can get a cheap USB stick that can mine as much as an expensive i7 processor) but other cryptocurrencies were specifically designed to make the gap between GPU and CPU mining much smaller and make ASICs not economically viable.
As a pure guess I'm going to assume the actual return you'd see is a few hundred dollars per week.