The 2.4 GHz and 5 GHz bands are open. Everyone and anything is allowed to use them, so long as they don't exceed a certain broadcast wattage. Avoiding interference is the responsibility of the operator.I'm not claiming in any way that you're wrong, but if you're right, someone's (B&G or DJI) is probably violating FCC rules, or has managed to spectacularly mess up their wireless implementation.
These bands were opened because things in the atmosphere (mostly water vapor) rapidly attenuates the signal. That makes them not very useful for long-range communications, but almost ideal for short-range open broadcasts (e.g. your WiFi router does not interfere with your neighbor's WiFi router because of signal attenuation). The 2.4 GHz band in particular surrounds the 2.45 GHz frequency used by microwave ovens, where the signal attenuation by water is so great that it can be used to heat food (and why older WiFi would go out whenever someone used the microwave, and can still cause problems for bluetooth and wireless mice/keyboards).
Same goes for the new open 60 GHz band (signal absorbed by atmospheric oxygen, used by the somewhat rare 802.11ad for high-speed wireless over a few meters). The older 600 and 900 MHz open bands (mostly used for analog signals like walkie talkies and wireless microphones) are also under the same guidelines. You're not allowed to exceed a certain broadcast strength, and avoiding interference below that is the responsibility of the operator.
There are various cell phone apps which will let you scan for nearby 2.4 GHz and 5 GHz signals. Though they may only show you WLAN channels being used, not RF use per se (e.g. you might not see interference from 2.4 GHz bluetooth connections). If you're aboard a boat at sea, it's almost guaranteed that any interference is being caused by something else aboard your boat. If you're gonna operate expensive equipment which relies on a wireless signal (like a drone), it's probably worth paying for/puting in the extra labor to run wires to connect things like a wind sensor.