Poa can get bumpy, but quite a few of the putts they grouse about are just plain misreads. IMO, the players have a very hard time putting on greens with so much contour. I didn't attend this year, but from attending it past years it is really surprising how often these guys seem completely baffled by even the shortest putts there, and how often they misread and miss hit them. Four and five foot putts there are very difficult, and it takes the pros out of their comfort zone. They can blame the bumps, but well struck putts would go in.
A few of the putts they showed on t.v. that did actually get bounced around a bit were straight down hill where gravity is providing most of the momentum, and I guess it doesn't bother me that they don't always get the purest of rolls after having left themselves in such spots.