That bw simply isn't available in the part of the RF spectrum allocated to us between a couple TV broadcast channels (72 MHz).
The article isn't about staying at 72 Mhz either. It is pushing for a whole new set of frequencies. However, while sperad sprectrum may or may not be viable for 72 Mhz, frequency hopping would. But that was not what the article was about. The issue is how busy the 2.4 spectrum is or soon will be. Lots of stuff coming so need to start pushing for this now.