Earlier quoted context omitted.
Jeff needs an art director doesn't imply anything more than that. It could be him, it could be another full time employee or it could be something he has a freelancer develop at the start of the project.
And it seems like he focused more on making sure that his artists were replaceable, even at the price of a hodge-podge style. The criticism is legitimate - it doesn't seem like Jeff has invested in his own ability to direct art.
Then again, the older I get, the more I think the same should apply to developers. You should never lock knowledge inside one person's head, but the idea that you can take over a project without its original creators doing a years long hand off is naive, and leads to all the expected pathologies.
I remember a new $250k CTO saying he was amazed our code didn't have abandoned parts nobody wanted to touch ... this is how professionals are supposed to work, not something they discover "late" in their career.