What is the difference between doing an act and defending someone else doing that act, from a hypocrisy perspective?
It's almost as if you're saying that you'd never kill a dude, because killing is wrong, but boy are you sure glad someone else killed that dude because he sure needed killing!
If the nature of Bush's "vacationing" was significantly different from Obama's, there might be something to be said... but in that context, we can't accurately compare Trump yet because he hasn't been President all that long. We don't have enough data to qualify the type of "vacationing" he is guilty (or innocent) of yet.
It is also debatable how different Bush and Obama really were, considering how a President is never really on vacation. Further, in the context of this particular political hot button, Obama is as guilty as Trump of using the outgoing administration's "vacationing" as a campaign platform and then not living up to the promise. If you'll recall, nobody slammed Bush for playing golf, but they sure gave Obama hell over every round he played. "Golf" became the term du jour for wasting time during Obama's tenure... and now Trump dares to play golf? How dare he?
I agree, it's all pretty stupid and hypocritical. Again, I contend that a President is never really on vacation, and that his weekends are not really his own. But accusing one side of being hypocrites while not recognizing that the other side essentially did/does the same thing is, itself, hypocritical.