You are actually conflating two separate issues:
1. Whether users should be able to run any software (binary or not, proprietary or not) which they happen to have access to, on hardware that they own
and
2. Whether it is right for people to distribute, to users, software which is useful for a purpose, and therefore attractive, but where the users cannot change or even inspect the software itself (and cannot hire anyone else to do these things for them).
The issue at hand was the first one, and you answered by talking about the second one.
I believe the usual Free Software Movement arguments go like this:
For the first question, it is obvious that users should have a right to use the things they own however they wish – otherwise it can hardly be called ownership. For the manufacturer to give such restricted hardware in exchange for money, but still retain this degree of control over the hardware after the transaction, should therefore not be allowed to be referred to as “selling”, since the recipients/possessors of such hardware cannot usefully be considered the full “owners”.
For the second question, while it is obvious that it is unethical to tempt users to give up their freedom to change and inspect the software, or have it changed or inspected (since this checking and tinkering is one of the things which drives a good society), it is certainly not obvious that it should be out-and-out illegal for anyone to offer such unchangeable and uninspectable software to users.