You're intentionally conflating scale here to make them seem the same.
> no warning that somebody/something is ingesting the repo
An individual reading code on their own time is not the same as ingesting terabytes to train a machine. No matter how much you believe in AI working similar to the human learning (it doesn't), they are not comparable.
> private profit
Again, the difference between an individual reading code to work for a salary is orders of magnitude different from ingesting terabytes of code so a company can create a new feature. Claiming these things are the same only makes sense if you ignore the massive differences in scale and the differences between how humans and machines learn.
> Is it unethical to use software for profit?
When the licenses explicitly say that if you use the software for profit it requires attribution, the answer is clearly yes. My code on github is licensed such that if you use it, you must say where it came from. The only way this isn't at the very least unethical (because it goes against my wishes as owner of the code) is if you argue that github isn't "using" the code, which clearly isn't true, because if everyone was able to opt out there wouldn't be a product for github to be working on at all.
> no warning that somebody/something is ingesting the repo
An individual reading code on their own time is not the same as ingesting terabytes to train a machine. No matter how much you believe in AI working similar to the human learning (it doesn't), they are not comparable.
> private profit
Again, the difference between an individual reading code to work for a salary is orders of magnitude different from ingesting terabytes of code so a company can create a new feature. Claiming these things are the same only makes sense if you ignore the massive differences in scale and the differences between how humans and machines learn.