Technically it's of course doable without too much headaches. But it causes some other headaches: One is IP protection: If you provide the enduser with a way to

Technically it's of course doable without too much headaches. But it causes some other headaches: One is IP protection: If you provide the enduser with a way to upload arbitrary code which might often get run with root rights (because that's what the application requires) then you essentially provide the user a backdoor that gives access to the whole system. Which then can be used extract everything including proprietary code and also exchange other components and not only the GPL ones. It also causes headaches regarding device qualification and associated warranties: In many industries (automotive, medical, etc.) devices have to go through a very rigorous qualification and test process, which ensures that exactly the 1 software snapshot on the device is OK. The manufacturer then takes liability for that and gives warranties. If the customer can exchange some parts of it then the device basically counts as untested, and nobody can and will guarantee anything. Device manufacturers will be scared, that they could get sued for device malfunctions that are caused by arbitrary code injection. It might of course be a solution that the user-code upload process triggers some anti-tamper switch which auto-revokes the warranty/liability. But I think as a car manufacturer you don't want to give the user a way to drive around with untested code, which might cause really really big headaches if an accident happens with it. Lawyers will discuss endlessly if the tempered software could have been the root cause or not, and even if it is the manufacturer might get bad press why he allows endusers to decrease safety levels.