To get in the obligatory first (cheap) shot, the B-52 didn't enter service until 1955. B-25s were in the second world war.
Transposed numbers aside, I'll play devil's advocate and point out, that for most people, free games are one offs. Mr. Kim's index doesn't have a sort by author feature, but I'd wager that only a handful of people appear more than two or three times. At the very least, we're talking something closer to restoring classic cars than building plastic model ones.
Thing is, we seem to be together more because "Games are really awesome" than free-ness is awesome. People like Linux, open office, and wikipedia for what they can do, and the fact that its done cheaply is icing on the cake.
Not that I wouldn't love to be proven wrong about this of course. I don't mean to be so pessimistic about this, but there do seem to be reasons why we don't have the extensive reach of webcomic communities and the like yet. Hopefully I'll be more cheerful in the morning and better able to asst this great endeavor.
Returning to the question of "does offering stuff for free hurt my business", I'd point out that there is a very successful set of economic principles based on giving something good away for free. It is the loss leader concept of economics, often called the King Gillette Principle - "Give the razor away for free, and then sell the blades". Strange Fact - since the Mr. King's safety razor was introduced, no US president has had a beard. Not so strange fact - a lot of game companies take advantage of this. Quite a few model producers give away the rules for their war games, then just charge for the figures.
Even if you're not charging for supplements, a free game can be your resume, your practice, or your advertising. It can build up some good will and as always, let you be proud of being a philanthropist.