Because when Bush took a vacation, he went to his house in Texas and took staff with him. Obama goes to Hawaii or Martha's Vineyard or Aspen or wherever. Not to mention that Obama has spent more time on the golf course than any other president in history.
Now, I think that playing golf is a good reason to not vote for a president. It's right up there with smoking a pipe as a pointless waste of time, money, and other people's attention.