We have to talk about economy and role free software plays inside
capitalism. Free software is free of value, it is not scarce, everyone
can take it for free (ignoring service and tux-stuff). Why should
companies pay developers developing stuff free of value? From the
narrow standpoint of a company this is burning money. But they are not
so dumb.
Using my criterion of having slim interfaces to the money world and
having money not playing an internal role, then this is valid for free
software projects with paid developers: you have a constant flow of
money into the project, but the money is not used to generate more
money by producing sellable products. On the contrary: There is no
money or product-to-market flow to the outside world. This is
essential, and this is my point!