Space station economies are too prone to become "palette"-like. We need to be able to restrict certain economy to keep it pure and focused.
Basically in any case where you care about a stations imports, exports, or mission-related consequences of those. Obviously not everyone will - if you don't care about station economies, you don't care about station economies and they could all be fixed at Colony type for all the difference it would make.Apart from making things feel less real and messy why would most of us want to limit economies in this way?