Because I do.
These Haitians have a choice...stay in Haiti, or not.
They make a conscious decision not to stay in Haiti, and instead enter another country illegally.
When you make a choice to put yourself in a situation that may be detrimental to your own well-being, the consequences of your decision can hardly be called slavery.
No one is buying them or selling them.
Once again you are defining excessive government control and abuse of power as free trade, and continue to advance the notion that more government control of trade, giving the government even more ability to abuse their power, as some sort of solution to already existing government abuse.
So you claim they are volunteering to be a slaves? By your logic, Americans can make illegal aliens slaves too.