His version of bi-amping isn't the same as using a pair of receiver channels to drive full-range audio signal to a woofer, though. His version is the way it was intended and is used in PA systems, which use completely different drivers/crossovers/processors and equalization from what is normally used in a home stereo or theater system. Technically, anyone using an amplified subwoofer and its high pass filter is bi-amping. I question biamping when the speakers have jumpers or bars to connect the high pass and low pass unless there's some way to make sure the levels will be well-matched.
If channels of equal power are used, only a little more headroom and a little output will result in a home audio system but when a large-venue PA is being designed, the power levels they use dictates that separate amps be used for each frequency range since any passive crossover will have at least 3dB of insertion loss and when a system is already in the 50KW range, not only will they need to use twice as much power (Mo' money, mo' money, mo'money!) losing half of the power to insertion loss and the heat generated in the passive crossover means that if a component fails, serious sound issues will result. With passive crossovers, if the crossover fails, they can replace it in the rack and not have to send a rigger up the array to pull it out of the speaker cabinet in hte middle of a concert.