At the individual developer level, you are correct. There are quite a number of people who prefer, to varying extents, to work on FOSS software and who will acc

At the individual developer level, you are correct. There are quite a number of people who prefer, to varying extents, to work on FOSS software and who will accept certain amounts of disincentives, inconveniences, and sacrifices to do so because they're outweighed by the personal incentive of working on such projects. Joel is talking at the level of corporations, not of individuals. All of his examples are of the strategic move of a company, not the personal belief of an individual (or the collective action of a group that is united by their beliefs). And the major take-away is, you don't need a non-monetary incentive to support FOSS, because there are monetary incentives. Open-source and profit-motive are not inherently opposed. So yes, the assumption he's making is that money is an incentive for promoting open source. For some, especially for companies, it is. For some, it is not. It's reasonable to expect that when companies are supporting it, they have something to gain by doing so, and Joel is spelling out how. That doesn't invalidate the personal motivations that some people may have, but neither do those motivations invalidate the more traditional monetary motivations that the companies (and some individuals) have either.