There were some valid contributions and other things that needed improvement. However, the maintainer enforced a blanket ban on contributions from AI. There's some rationalizing such as tagging it as a "good first issue" but matplotlib isn't serious about outreach for new contributors.

It seems like YCombinator is firmly on the side of the maintainer, and I respect that, even though my opinion is different. It signals the disturbing hesitancy of AI adoption among the tech elite and their hypocritical nature. They're playing a game of who can hide their AI usage the best, and everyone being honest won't be allowed past their gates.