You might have purchased a particular device, but you generally don't have the rights to the software or firmware that runs it.
If you're truly concerned, you should support manufacturers that leave their system open by design, or support open source devices, and contact manufacturers describing your concerns.
But the tradeoff wars of freedom v. security were lost long ago. The idea that one should shoulder any blame for choices is lost on a generation that needs YouTube videos to cut an onion. Likewise, a significant number of individuals can't be bothered to change their router password from 123456, and an even greater number of folks think the govt needs to regulate the internet to keep it fair and safe for everyone.. Forced encryption with no choice by design is a feature, not a bug.
Use open source or