Neary: Rotten to the (Open) Core?

Because without any explanation, "free software" would simply default to software at no cost for most people, as it is today. If a company wanted to co-opt the libre meaning "Free Software" for nefarious purposes, they would have to at least explain how free has two meanings, and that the gratis one isn't the one they refer to by "free".

If a company would put out a shareware version as free software, it would simply mean that, a version of the software at no cost; they wouldn't even be lying.
If they would want to use that to subvert the libre meaning, they would have to position it as "free, but not just as in no-cost", leaving open the question "but then free as in what as well ?"

Please note that I don't think open-source is a term not worth saving or guarding, nor do I suggest it should be dropped wholse-sale in favour of Free Software. I am responding to the statement that the term "free software" would inevitably have suffered from the same problems as the term open-source, and that to believe otherwise amounts to being naive.