Latin America represents something close to 600 million inhabitants, and Argentina's agricultural output is far from that.
The source of the problem, as you call it, is in fact very complex. And I fear you can't simplify or explain it though the simplistic vision of Marxist class analysis. Do you think classic Marx lectures could teach Haitians not to make as many children as before?
When you have a devastated environment, there's not much you can do, aside from seeing this country and its society slowly dies out of its own agony.
I tell you: Within twenty years from now, Haiti will be on the verge of total annihilation, just like many Sahelian countries. And this will happen whether we decide to help them or not -even if this should not prevent us to help them: do we simply have a choice?-
We have only one planet. And its ressources are more limited than what we think they are, especially in developed countries. You cannot instantly transfer ressources from Argentina to Haiti thanks to a kind magic. Everything has a cost, not only in money, but also in energy.