Conway's Law for infrastructure / tooling, perhaps. If you have complete control over the organisation's dev process, and are willing to invest enough, you can

Conway's Law for infrastructure / tooling, perhaps. If you have complete control over the organisation's dev process, and are willing to invest enough, you can build something better than the default free / distributed / popular tooling. This is probably partly enabled by the fact that they don't have to care about trading patches easily with the outside world. Then, by rolling their own in-house workflow/infrastructure/tooling, they make it harder for outsiders to contribute, even if this were organisationally possible and desirable.