"RMS is not proposing an increase in productivity, he's proposing a massive disincentive to engaging in one of the most productive, highest growth industries in the world's history."

You say tomato, I say tomato...

Seriously: if you were explaining to a space alien what the distinction was, how would you do it? The only one I can see is all the subtle connotations of the adjectives and superlatives you chose to throw in.

I mean, the automobile was a "massive disincentive" to the horse breeding industry too. The gun put a ton of blacksmiths out of work. And secretaries and typists were an awfully big part of the world economy in the recent past too... All those people (figuratively -- really the fraction of the workforce they represented) are now doing other stuff like building web apps. And the world is a better place.

"Productivity" is a quantifiable metric. Either you pay programmers to duplicate effort or you don't. In the latter case, productivity is higher by definition, and no amount of adjectives is going to change that fact.