Let me put this out of the way: I don't think Korea will dominate the Dota scene. This comic, like many, exaggerate the situation a bit for comedic purposes.

If you follow the League of Legends scene, you see it heavily korea dominated to a point other nations import korean players to boost their roosters, and given how close both games are it's not hard to imagine koreans would fare well in Dota too.

Even with the small popularity and little support (they don't have local servers) the boys from korean MVP managed to reach 4th place on the Shangai Major.

If Dota ever got popular on Korea I'd expect them to be a dominant force in the scene but for better or for worse, the interest just doesn't seen to be there and thus this particular game will remain korean free.