Is it resulting by the assumtion I was hired by a company as software developer then I have to give source code to the payer?
As a software developer once I had the impression that partner company not only wants me to develop a software, but because they have not a clue about my field, rater they want learn framework from my code. From other side I did not felt I can learn anything from them, they kept strict secrecy, shared with me only the minimal documentation / info, changed back to their native language as soon as sensitive business topic came up.
Can you imagine a condition of a contract is drawn up that I make binary code / framework, what they are allowed to use only in their application, but I take the responsibility that code satisfies specification, it is tested and for a certain period in the future I will fix bugs come up?!