Colin's statement was in the context of the question of BSD vs. GPL licensing.
RedHat's model it's clearly more effective than simple charity, but I don't see a difference between RedHat and any other OSS-reliant contributing vendor. As an example, Juniper funds FreeBSD development based on sales/support of their high-end networking products, and contributed the MIPS port included in FreeBSD 8:
The main difference is that these companies make their money by incorporating FreeBSD into their products, are not required to provide all the source to their products, and thus can contribute back improvements as they see fit.
BSD benefactors get a good feeling and a word of thanks for their contribution.
The difference in the amounts of money received by both institutions shows how much are people willing to pay for the former vs. the latter.