Kyle, I dont think maintenace is the problem.
The winning scores were (I think, off the top of my head)
Masters: 280 (-8)
U.S. open 285 (+5)
British 272 (-18)
PGA 272 (-18)
At Augsta there is almost no rough yet players had a more difficult time on this course then 2 of the other 3 majors (and Augusta isnt really supposed to be a US Open anyways). The way the course was set-up, I think angles were challenged, especially with such bold green complexes. Without these tough, windy greens, I dont think Augusta would have been much different then Medina or Hoylake, where the greens are a lot less severe.
At the US Open, the rough is so thick and where angles are so important to having a good shot, the long rough makes for a good setup. If WF played to it's normal par-72 the scores would have been right around par, which is IMO where scores should be. But think about it, WF has nasty greens to.
Now, Medina and Hoylake dont really offer much with defending par with their respective greens. For this reason many more putts were holed and scores went a lot lower, and because more putts had less break angles didnt really need to be challenged. Tiger Woods hitting long irons into almost every hole yet still blowing away the field proves this IMO.
In the end, I do not think maintenace or course setup is really the problem.
I mean, these guys are so good that scores are going to be somewhat low one way or another.
I think the real thing that makes some major courses better than others is bolder greens and green complexes.
As showed by the toughest two majors this year, we need more of them to challenge these guys...