Devil's advocate: why? Why do people need to make sure to disable it?

Is this the "but privacy!111" stance, or the Dog in the Manger stance ("I'm not being paid for it, so why should anyone else benefit?"), or...?

Also from a security perspective. People have been able to extract copyrighted code / API keys some LLMs have been trained on before. If you opt-in to this, your / your company code will be used to train and improve the model. People may then be able to extract that from the model. Another threat vector.