One result of our recent case study research on inner source is that companies may not always need platform organizations to get to a platform of shared reusable assets. They will certainly need platforms, but they won't need a dedicated organizational unit to develop and maintain this platform.
You don't have to read the research paper to come this conclusion; common sense is just fine: Through the Apache Software Foundation (ASF), for example, companies like IBM, Oracle, and SAP are able to collaboratively develop the infrastructure of the Internet. The ASF has almost no employees; all work is done by the participating companies (and a few individuals). If companies like these, who fight each other to the death in front of a customer, can join hands to develop competitively non-differentiating software, why can't organizational units inside software companies do this?
This is the idea of inner source: You don't always have to have a dedicated organizational unit to work on a particular component. If the component is of broad enough interest within the company, users of this component might as well chip in and collaboratively develop the component. In the extreme case, and perhaps this is also the best case, no dedicated organizational unit is needed any longer for the development of shared reusable components.
The idea of doing away with a platform organization flies in the face of conventional wisdom. Given that textbooks tell you that product line engineering requires a dedicated platform organization, and leading companies are typically set-up this way, doing away with the platform organization may indeed prove to be too disruptive in the short-term. For this reason, we have developed several solutions that let companies keep their platform organizations.