Bitcoin allows people to be their own bank as well as allow many of those previously unbanked, who couldn't before, participate in the economy, which is a good thing.
What makes you think that the "unbanked" can not participate in the economy? Most of them are actively participating in their local economies by bartering or using physical cash. The term "unbanked" is horrible, because it generates the perception that people, who are not using banks are somehow dumb and need help to participate in the glorious banking world. But in fact, the opposite is true: These people are doing it right!
Of course Bitcoin offers immense opportunities for the world economy, because it "unbanks" all people, freeing them from the restrictions and costs that come with using banks and other financial service companies, especially for international transactions. With widespread Bitcoin use, international trade can be lifted to a whole new level. Direct international trade will be much easier and the world will grow more together because of it.
ya.ya.yo!