> If that's the case why would somebody who has good ideas but poor expressive capability bother posting here if their comments are just going to get ignored over relatively vapid comments that are grammatically correct?

The main problem is that ai consistently is seeing making things worse. Take a look at the examples in Dang's link in their comment: https://news.ycombinator.com/item?id=47342616

In the ones I read the AI editing is either hurting or needs to be much, much better to help.