Community open source is open source that is not owned by any particular company. Rather, ownership is shared among a large number of diverse stakeholders. Given the right (read: permissive) license, commercial companies can provide extensions to the community project, earning a living. Since such extensions are a unique selling point of these companies, one might think that they would prefer to keep the community project small and limited in features to facilitate an easy upsell to their more comprehensive offering. This thought becomes particularly intriguing given that commercial companies typically hire the core developers of such community projects to bring the necessary expertise in-house, and as some argue, to influence the project to their liking.
I think that this common belief misses the point.