Firefox is non-free due to trademark protection, but that's VASTLY different to being non-free due to being a paid download, or being closed source, or patent licensing, or restrictive licensing terms, and so on. It's almost irrelevant to the parent poster's comment to claim that.
It's not really a big deal, but the trademark restriction does mean you can't just redistribute Firefox as-is. Whether you count that as non-free is subjective.
I agree there's some subjectivity but "you can't just redistribute Firefox as-is" is NOT subjective. That is flat out wrong. You can redistribute Firefox as-is. What you can't do is redistribute modified Firefox and keep the name.
