No, I think that it should be rebuilt. While the situation is dire, it is not unheard of for a country to be able to rebuild and become even more powerful than it was before. Think about Japan around the end of WWII. Strapped by war, economy run into the ground, Hiroshima, Nagasaki ... There was a time when anything made in Japan was seen as being junk. Japan is earthquake prone, there aren't many natural resources, but within 50 years, they were able to become one of the most powerful countries in the world. I still have hope for Haiti.
I think that one of the things that can be done in Haiti, is to have all of their debt forgiven or at least a more significant portion of the 1.8 billion than the 500 million that is currently on the table. That way the country can start with a clean slate. There are many parts of the country that can be salvaged. What I would really like to see is to have the people of Haiti - not only the people there, but the people off-island be able to come to concensus about the rebuilding process along with other countries. The Dominican Republic, which has the other 2/3 of the island is not as mired in poverty - there's got to be something that can be learned there. Additionally, I would love to see Haiti use what it does have. The key I think is looking at how to get people working to rebuild and also finding some other way to generate revenue in the economy than the agriculture sector. With over 80 percent of the people in poverty and almost 50 percent of the population being so young (18 years or younger), this is no easy task. Taking some of the money and pouring it into education - to create a skilled labor force, I think would help a lot. If they can use some of the foreign aid to build buildings and roads that are to code - they can train haitians to work these jobs and start lifting them out of poverty. Then, with proper leadership, they can look for ways to get money coming into their economy instead of having to rely on foreign aid.
And for the record, I think that KungFu Panda's response makes no sense. Obviously, the reason that they had poorly built buildings and roads to begin with is because they don't have the money to purchase the materials to build better ones.