Jordan,
I will try my best to explain why I believe bad is an accurate word (And please understand this comes from playing 33 of his courses in 9 different states). He IMO lacks the ability to understand what a golfer will and should do on any given hole. As such, on every course of his that I have played, he has greens misshaped to the fit of the shots that should be played, his bunker work is typically atrocious, his green complexes run the gamut from unspectacular to illogical and he lacks an in depth understand of routing to the point where he imposes cart-ball on properties that did not need it. I'll admit that some of his really putrid work, like Oak Pointe, require carts becuase of the wetlands, but many did not and it is just the way he routed the course.
I have told this story many times but I think it sums up Hills best. UofM brought him in to renovate Alister Mackenzie's work on their course. #3 was a fantastic short par five with an incredibly severe back to front green that could hold a very well played wood. The hole had a line of trees up the left side, a severe dogleg left at the 140 yard point around the trees and a very cool old bunker at the 250 yard point off the tee on the right side. The fairway slopes hard right to left. An intelligent golfer could see that the hole could safely be played 3-Wood off the tee, 5-iron to the bottom of the hill, Wedge to the green. For the golfer who wanted to take a risk, he could hit a Driver with a big fade. If he sliced it, he was dead to the right, if he hit it straight, it was in the trees but a huge fade past the bunker on the right would give a view of the green. Hills added 40 yards with a new back tee. An intelligent designer would have put the tee back and to the right, so the required shot could still be hit but new technology factored in. Hills put the tee back and to the left. By doing so, a fade cannot be hit as it catches the tree stand. Now the only shot that can be hit off the tee is a draw and because of the slope of the fairway, the draw kicks even further to the left and the option to go for the green is gone. Instead of restoring a terrific Mackenzie option hole with a risk/reward component, Hills renovated in a vacuum and his lack of understanding of golf eliminated the charm in the hole. I can think of at least 20 other examples where Hills has done this.
Bay Harbor is really his Titanic. I do not say this lightly but I believe that he had a better canvass at Bay Harbor than Dye at Whistling Straights or Doak at Pacific Dunes. Imagine a property with 9 holes of land like the 3 quarry holes at Black Diamond and 9 holes of windswept dunes that rival anything at Bandon. The work there is so visually striking (Because of the property) that the course opened in everyones top 100. After playing it a couple times though, almost all golfers noticed that the course lacked soul, charm, options, and thought. I do not know Hills and from everything I here he is a charming guy and I certainly do not begrudge him his success. I do however believe bad is a very fair term to describe his architectural prowess.