That's not telling people to not use LLMs. It's telling them that using them in a specific way is not helpful.
Reading beyond the first line makes it clear that the problem is a lack of comprehension, not LLM use itself. Quoting:
> This isn’t about whether you use an LLM, it’s about whether you still understand what’s being contributed.
Then they could just say "understand what's being contributed" and not have to mention LLMs by name at all. They are very clearly blanket discouraging people from using LLMs at all when contributing to their project.