As I stated above, I tried to give a simple answer. The article you quoted goes into depth on the subject and is an interesting read.
What I got out of it was that if you're going through the speakers internal passive crossovers there will not be much, if any, power gain from using multiple amps.
The way to get the true benefits of bi-amping is to use an electronic crossover rather than going through the internal passive electronics.
This approach certainly has power benefits, as you are limiting the power bands of the amplifiers and there are no passive components in the way to drain off power.
I'm not sure if electronic bi-amping is what Mitch4t was referring to, but I suspect not. It would entail removing all the passive crossover components from the speakers and then buying a good electronic crossover or having a custom electronic crossover made for the particular speaker system. This could get costly by the time you add the price of the extra amplifiers and electronic crossover; plus many folks would not have the wherewithall to tackle such a project.
But if you did undertake such a project who could resist upgrading the internal wiring and maybe having it all cryo-treated, including the connectors. But why stop there?...