Undoubtedly this is payback because Cubans don't support Democrats.
Additionally, I'm sure Obama also thinks it's unfair that Cubans get to come here legally while other immigrants have to sneak in. Just because they are politically oppressed shouldn't "privilege" them. The other immigrants are economically oppressed!
And, although I'm mocking that thinking, I'm certain that he had these and other motivations- pay back the disloyal Cuban immigrants (Punish your enemies!) and make it fair for other immigrants (Equality!)
If I recall correctly, Cubans are also among the immigrants who do much better than the average immigrant as well. Still more striking a blow for "equality."