Leave it to George Will to have a basically solid argument (i.e. the Republican stance on Cuba is misguided) and then to muck it up. In particular, he argues that Obama achieved too little.
There are two reasons for questioning whether Obama really tried. First, he is generally congruent with, and partly a product of, academic leftism. Hence, he might be tinged with the sentimentalism that has made Cuba a destination for political pilgrims too ideologically blinkered to see the extraordinary sadism of Cuba’s treatment of its many political prisoners. Second, Obama is so phobic about George W. Bush’s miscarried “regime change” in Iraq that he cannot embrace, or at least enunciate, a regime change policy toward Cuba. Regime change, however, must be, at bottom, the justification for his new approach.
This "academic leftism" focused on Cuba idea, like so much else related to Cuba, is a Cold War-era phenomenon. I know plenty of academics who consider themselves on the left and they do not romanticize Cuban socialism. Even 15-20 years ago, in all my years of graduate school--when Latin Americanist professors impart their views on so many things to graduate students--I never heard that sentiment ever come up.
Next, you do not have to be phobic about George W. Bush to avoid a policy based on regime change. You just have to be intelligent and conscious of historical precedent pointing to disaster. What Will clearly does not understand is that Obama is simply saying that the U.S. won't be the obstacle anymore. We've helped prop up the Castro regime and now we'll get out of the way. Calling for regime change would've backfired. As always in Cuba.