Plenty of people care and do things about them. If you are interested in becoming one of them, start reading up on the topic. Without experience, the most good you can do is to donate money to organizations that you think are trustworthy and have reasonable plans and goals.
I've got a chunk of money lent to various people trying to start / expand businesses in their countries through Kiva (
www.kiva.org), which is a good place to start as you can get in with as little as 25 or so dollars. If you want to funnel your money to Haiti, specifically, look into donating to the Red Cross, Doctors Without Borders, or similar organizations.
The fact that you never gave a damn about the developing world before this earthquake nailed Haiti doesn't mean that nobody did. Also, the sad truth is that many places on this earth are in such bad shape that nothing short of a major government action has the capability to unfuck them in the near future. People do what they can.