It also gives a clear opportunity for the individual to disclaim specific liabilities in exercising specific freedoms, and hence the state a way to say that option must be available, if people want to choose something other than the restrictions manufacturers want to impose. If you want to sideload whatever that's fine, but specific liability protections from unvetted software are off the table. Don't like that bootloader? That's fine, but OEM isn't responsible for what happens next.