Turning those radios off provides little in power savings but cripples other functions. Bluetooth is used in handoff, watch connections and AirPods for example. Wifi is also used for handoff and continuity and greatly increases the speed and power efficiency of location services. Losing your watch connection because you wanted to disconnect from the car, or making Location Services worse because you wanted to disconnect from a wifi network isn't good.
Generally, people who are using CC to disable them just wanted to disconnect from something. A public open network that's preventing you getting to the internet for instance. You can of course still turn them off completely in settings but the logic goes that since that's the minority usage, that's the one gets buried a little deeper.