David, That's correct. There are many more factors that could exist, but I was trying to narrow the focus to those which are necessary and sufficient.
Many people are confused, and even distanced, by open source rhetoric.
The principal source of those reactions lie in our failure to understand and promote the aspects of open source which will bring success to the computer industry in OUR society. My contention is that open API's, data formats, and OS infrastructure are the ONLY aspects of open source that are both necessary and sufficient to generate the most possible benefit to business in our society. Licensing issues come into play because that is the legal mechanism we use to define and control the use of our open source resources. It merely maintains the open source availability of any piece of software which anyone has chosen to license under its terms. If people understand that the true economic value of a piece of software inures from its open source nature, then that software will continue to fulfill its role as an open conduit of other IP that can be used to generate the profits a business in OUR society requires in order to survive.