There's a big difference between a 501(c)(3) non-profit like the FSF asking for copyright assignment, and a for-profit corporation doing the same. The latter c

There's a big difference between a 501(c)(3) non-profit like the FSF asking for copyright assignment, and a for-profit corporation doing the same. The latter creates an uneven playing field, and other corporations are generally loath to assign their "IP" to a competitor, which tends to prevent the mutually beneficial collaboration that is the biggest advantage of successful open source projects.