Well it fixed their problem enough, and filing a PR was the level of effort they're willing to put in. It might help someone fix it properly, and it might help someone fix it enough to get moving, so it's potentially good for the origin and good for the users and if not, the origin can close the PR.

I'm getting very confused by this attitude.

It's broken code. It's bad code.

Never, ever submit bad code. You're just making even more work for everyone.

Its far worse than doing nothing at all. And if you want to highlight the problem, just raise an issue, point to the problem.