I didn't take incompetent as an insult, but in its straightforward, descriptive sense: the people were not competent at the jobs they were assigned to (and, presumably, weren't given sufficient help in becoming competent)
Would they be happier producing 10,000 tractors that would actually last, instead? Maybe. Would they be able to do that right away? No, but with some practice it could be done. Could they produce better tractors with the constraints that they had? I don't think so.
You will undoubtedly see the same pattern all over the corporate world.