I think also that people don't realize what the GPL does to create permanent code monopolies. This would be much more equitable if the author were also bound to the GPL, but in fact one of the prime uses of the GPL is to prevent others from selling commercial licenses while retaining one's own right to do so.
Modify the code and, as required, license it yourself under the GPL. Now you can sell commercial licenses, too.
I think he mean, "dual licensed business model". One is the GPL, the others is "as long as you pay us, you can do whatever the shit you want" license.