You are using the word "owner" loosely. DJI does not establish ownership of these drones. Logging in and binding is not "ownership." Legally, this is personal property and for the most part, a bill of sale or simple possession is enough to prove the drone is yours especially in the absence of anything to refute it. There is no title involved with this drone and there is no legal transaction in order to transfer it. For DJI to establish a different level of "ownership" and then set parameters based on it is nonsense and will likely one day ultimately leave them (or the seller) liable from a civil perspective unless they come up with a more robust remedy.DJI has no need to get involved with Account binding. It is Simple to Do and if you are the owner you have this information readily available. Pretty Airtight.
Ask the cellphone carriers what happened when they used to lock down phones and "never" unlock them. Please don't use the Apple model because they got it right. DJI should take a page.