Except he doesn't actually care if you charge for your code. All he cares about are the rights of the consumer. Now, supporting these rights does make it somewhat more difficult to charge for your software, but it clearly isn't impossible: there are companies built around free software. Moreover, if everyone provided free software, it would actually be easier to charge money for it because you wouldn't have to compete with proprietary software and drm.
Even then, RMS has no problem people selling and buying software, he only cares that, once a user has acquired the software product, he can alter it (that's the "free as in freedom" part, as opposed to "free as in beer" which RMS — as far as I know — doesn't really care for).
Now building a business with these constraint is not — as far as I know — a solved business model in the general case, but saying that RMS wants developers to "give their product for free" is a complete and absolute misrepresentation of his position.
