I very much agree with your conclusion though.
And yet, computing professionals were much less free than they are now. Because programmers almost universally worked at the King's pleasure.
The exception to that rule was small garage shops. Like Microsoft and Apple.
What does it even mean to say "When you bought a program..." in the context of Open Source? Of course if you paid for it, it isn't open source.
But then see also Pysol; a free open source program that was being sold by sneaky companies. The devs decided to stop releasing it.
(http://bytes.com/topic/python/answers/41344-pysol-using-qt-c...)
As for serving Powers That Be - most of the creative people do it right now, only Powers changed. Some time ago, most disposable income was in the hands of aristocracy and later rich merchants. So they were served. Now due to huge technological advances pretty much everybody has disposable income - so artists cater to everybody. Some of them still cater only to the richest, of course - everybody has his niche. But except for the distribution of the disposable income, not much changed.
- Serfdom was still legal in most of Western Europe.
- Professional artists occupied the same social rung as prostitutes.
- An intellectual professional's primary option for making a living off his (that pronoun being sufficient for the era) work was patronage.
- The vast bulk of intellectual output served the primary purpose of glorifying the political and religious Powers that Be.
Of course that doesn't imply that the current copyright and patent law isn't enormously out of hand, or that it doesn't largely function to the detriment of creative professionals thanks to the grotesque ways in which it has been amended over the past three or so centuries. But the basic idea is admirable, and it can and should be salvaged.