You could make separate versions of an LLM depending on the license of its output. If it has t produce public domain code, it can only be trained on the public domain. If if has to produce permissive code (without attribution), then it can be trained on the public domain and permissive code. If copyleft, then those two and copyleft (but it does not solve attribution).
> Companies can also buy code for feeding the model after all.
We've come a long way since the time slavery was common (at least in the west) but we still have a class system where rich people can pay a one time fee (buying a company) and extract value in perpetuity from people putting in continuous work while doing nothing of value themselves. This kind of passive income is fundamentally unjust but pervasive enough that people accept it, just like they accepted slavery as a fact of life back then.
Companies have a stronger bargaining position than individuals (one of the reasons beside defense why people form states - to represent a common interest against companies). This is gonna lead to companies (the rich) paying a one time fee, then extracting value forever while the individual has to invest effort into looking for another job. Compensation for buying code can only be fair if it's a percentage of the value generated by that code.
> So beside the injustice you directly experience right now over your own code probably being fed into AI models, do you fear/despise anything more than that from LLMs?
Umm, I think theft on a civilization-level scale is sufficient.