The figure's misleading, because mining (these days) is done with specialised hardware: ASICs, chips dedicated to calculating SHA256 hashes (or whatever algorithm your favourite coin uses), which can calculate those approx. 105 times times faster (per second per $) than a general-purpose CPU -- but can't do anything else.
So that implication may well be true in the sense that if all the worlds computers turned to mining bitcoin, the total mining capacity would only be increased by a couple percent over what it is at the moment (due to general-purp... (read more)
@habryka followup: I'm guessing no luck with this?