A hardware circuit can't be changed; that's its nature. If it's acceptable for a device to be implemented with internal circuitry that no one can alter, then an internal program that no one can alter is no worse.

Treat ROM firmware as circuit.

The equivalence falls apart, however, when the software implementation is not totally internal and some company can modify that code. For example, when firmware needs to be copied into the device to make the device function, or included in the system distribution that you install, that is no internal software implementation; rather, it is a piece of installed nonfree software. It is unjust because some manufacturer can change it but you can't.

Here, for your reference, ROM is fair for anyone, non-ROM that is non-free not fair.

But not think this imply "ROM better", but rather "make free software or no software at all". He want absolute freedom, you want usability. Which absolutely not what libre about.