A lot of software developers are doing what RMS says a lot of time. It's just that almost noone does it all the time.
It's clearly evident from the amount of GNU and GPL software out there that wasn't written by RMS that people are following his ideas. And that those ideas have succeeded, simply by the success of that same software in the marketplace.
It's not a failure of the ideal when developers of open source also write proprietary software to pay the bills.