Open Source is no business modell, is the finding of a study of the 451 group.
As the open source development and distribution model has been adopted, either partially or fully, by both startups and established software vendors, some of the assumptions about open source software have taken a back seat to commercial reality. For example, the idea of a community of individuals sharing the development of software projects for the greater good has been superseded by the image of a community of vendor employees sharing the development of software projects to increase code quality and lower production costs.
Similarly, the idea that the only way of generating revenue from open source software is through specialist vendors that make the majority of their money providing support services has also become outdated. There are now a wide variety of methods used by vendors to generate revenue from open source software.
On a completely unrelated note: The founder of the 451 Group has apparently recently been invited to Microsoft.