Why isnt ChatGPT open source?

I’ve seen several users wondering why ChatGPT isn’t open-source. From what I’ve gathered, OpenAI is somewhat concerned about the possible risks associated with making ChatGPT fully open-source. By keeping the code under wraps, they aim to prevent malicious usage and other unintended consequences that could arise if it were to fall into the wrong hands.

Behind the scenes ChatGPT probably does some summarizations, maybe vector embeddings etc. Overall it is not a super complex application and can be replicated in just a couple of hours with the API.

Why make this choice? showing the inner workings (especially full prompts) could help users to understand how answers get generated.

Please let me know your thoughts