One expects purveyors of proprietary software to be avaricious; that’s what being in business is all about. But Richard Stallman & Co?
Proprietary software companies want to give you their product – in exchange for money, to be sure. But Free Software advocates don’t want to let go.* They cling to their intellectual offspring, always retaining visitation rights, never letting it grow up and live its own life. Free software licenses want to ensure that the writer of the code can always see it in future, that it remains available to them forever. (IANAL: take this definition with a bag of salt. See wikipedia and its references for the true scoop.) They resist alienation, in the legal sense of the transfer or conveyance of property or some other right to another (from the Latin alienatus, from alius, “other”).
Now, wasn’t there this angry 19th century guy with a bushy beard who got worked up about all the ways in which workers lost control of their lives through being alienated from the products of their labor...? And wasn’t there this geeky 20th century American guy with glasses who riled people up by associating open source with communism? Ah, it all makes sense now.
* Actually, companies don’t want to give away their software, either – you get a license to use the software, not title to it. But heck, they’re greedy capitalists, so that shouldn’t be a surprise.