There are multiple situations where it would be desirable to turn off the 2.4 GHz radio on the Mac. The need happens when the access point provider uses the same SSID for both 2.4 GHZ and 5 GHz (Xfinitywifi hotspot network for example) and the 2.4 GHz band is very slow because it is shared by many other access points (apartment buildings for example). The Mac automatically chooses the strongest signal which is usually the 2.4 GHz one.
