There is absolutely no way you're using an LLM to rewrite the Linux kernel in any way. That's not what they do, and whatever it produces wouldn't be even a fraction of effective as the current kernel.

They're text prediction machines. That's it. Markov generators on steroids.

I'd also be curious about where that 15-20% productivity increase comes from in aggregate. That's an extremely misleading statistic. The truth is there are no consensus data on any productivity improvements with LLMs today in aggregate. Anything anyone has is made up. It's also not taking into account the additional bugs and issues caused by LLMs, which are significant, and also not a thing you want to have happening on every PR with kernel code, I promise.

Regardless of all of that, the companies with these LLMs are using free software to train their models to make money without making their models free and open source or providing a way for people to use it for free/open source projects, so this is a clear violation of every single FOSS license model I'm familiar with (most commonly used is the Apache one).

TL;DR; they are stealing code meant to be free and public with any derivative works, profiting off it, and then refusing to honor the license model of the code/project they stole.

This is illegal. The only reason why we're not seeing a lot about it is these FOSS generally have no money and are not going to sue them and potentially lose a substantial sum of their negligible funds in court. That's it. Otherwise, what they are doing is very illegal. The sort of thing any professional software development company you work for's legal team warns you about the second you start using an OSS project in your for profit business application codebase.

LLMs get away with it because $$$$$$$$$$$$$$$$$. That's it.

Edit: added link to security article with LLMs