The US President has unprecedented conflicts of interest in nearly every industry, but corruption is likely not the primary motivation for this ban. Chinese corporations have no rights to privacy or independence so if the government wants to audit, cultivate, or seize a company database, they can generally do so without cause, resistance, or even notification. This may be a security risk for those whose data is being captured or monitored.
Therefore, it would obviously(?) be foolish for any nation to use DJI drones to survey the majority of their own critical infrastructure (power grids, skyscrapers, military bases, shipping ports, etc.) and then create military tension with China. But here we are.
DJI might be a perfectly decent company and Trump/Biden/etc. might have perfectly legitimate causes for concern as China's oppressive corporate laws prove to have unforeseen military and economic benefits. So, while smaller countries can enjoy watching this all play out from the sidelines, America had to choose between either continuing to improve our relationship with China or encouraging them to partner with Russia instead.
Our choice to retreat into isolationism means that we now have to draw lines on what consumer product is or isn't an enemy surveillance device. Simple minds can see the potential of a Huawei, Mavic, Osmo, or even a wireless microphone to be used as a weapon of war, but it doesn't take much deeper thought to see the potential of apps like Avinox Ride being exploited either directly for surveillance or as trojan conduits to other networks. Obviously, the US can't just shut down every Chinese product since nearly every product is Chinese, but as we choose to become enemies with our primary supplier we'll have to keep trimming back on trusted devices, and DJI bikes might not be far behind microphones on that list.