At this point, I'll say Haze.
Statistically, the worst coaches of my time are Jim Colletto, Fred Akers, Ryan Walters, and Haze---probably in that order with Colletto being the best of that bunch and Haze being the worst.
I don't think Bob DeMoss belongs on that list at all. Yeah, he followed Mollenkopf and couldn't keep pace. But, he did go 6-2 in the B1G his las year as Purdue's head coach. None of the other bottom tier of Purdue coaches have come anywhere close to that. I would put DeMoss in the same category as Alex Agase, Leon Burtnett, and Danny Hope as below average but not the bottom.
My take on Purdue coaches since Mollenkopf:
Top tier:
1. Jim Young -- Purdue's best teams since Fat Jack.
2. Joe Tiller -- Consistent success if not great.
3. Jeff Brohm -- Exciting while it lasted.
Average by Purdue standards:
4. Bob DeMoss -- Tough gig to follow Mollenkopf, but a true Purdue man.
5. Danny Hope -- Not a lot of institutional support.
6. Leon Burtnett -- Take out the '84 team, and this looks MUCH worse.
7. Alex Agase -- Competitive but couldn't get Purdue back over the hump.
Bottom Tier:
8. Jim Colletto -- Great running game but no defense and questionable game day decisions.
9. Fred Akers -- No defense, no running game, no real plan
10. Ryan Walters -- It's not looking good.
11. Darrell Hazell -- Three+ years spent in the Haze.