The second worst is the unaware sort. The work doesn’t meet spec, and we don’t even realize it.
The worst is uncaring. We know the work doesn’t meet spec, but we don’t bother to fix it.
But there are other varieties, and some are worth seeking out:
There’s the incompetence of creativity and art, where the spec isn’t the point.
And there’s the dawning awareness of incompetence that comes from learning. We didn’t realize we could do better, and then we discover we can. That’s a critical step on the path to better.