"If Raymer tipped the dealers $100,000 after his 2004 WSOP win, I doubt anyone would consider him to be "cheap" for only tipping 2%."

2% was a great tip on a prize that large. Everything is relative. The bigger the prize the smaller the %.
There was also (I think 2%) with held by Harrahs for the crew. WSOP crew had a nice tourny from what I hear. They deserve it.