Just because you purchased the device, you think you own it?
What a novel idea.
It appears that Amazon feels that the owner should not be allowed to mess with their automated, remote, market research and sales tool's firmware.
I.E: The device is yours, the behavior still belongs to Amazon.
If you have been following this MR forum, you already know that more than a few of us are ticked off by that attitude.
("ticked off" - en_American Slang ; I don't know what the French would say.)