Ezra's certainly right to say that it's bizarre for George W. Bush to criticize Barack Obama on the grounds that "it'll send the wrong message" for Obama to hold a meeting with "a tyrant who puts his people in prison because of their political beliefs" considering that Bush does exactly that on a regular basis. Is it a good thing that the people of China and Russia and Saudi Arabia are, like the people of Cuba and Syria and Iran, ruled by dictators? Of course not. And if the lessons of history indicated that some kind of "no meetings ever" policy caused those regimes to melt and transform into wholesome democracies, then we wouldn't be having this debate.
But things don't work like that, and in the world as it is it's hardly practical to eschew all meetings with everyone whose political system you don't approve on. The question is, thus, whether or not this posture of creating a mostly arbitrary class of "bad guy" that we're going to take down with our awesome powers of snubbing accomplishes anything meaningful. Obama's contention is "no." Bush's contention is "yes" but he has absolutely nothing to show for it.
The frustrating thing is that the media plays along, designating "bad guys" as whoever the US government is designating a bad guy that week, while perpetuating the notion that the "bad guy" designation is linked to some sort of human rights badness when in fact it's just because they're bastards, but not our bastards.