"...Yea you would think they would buy one..."

I have never been there, but I have been in other poor countries, and you have to remember that most/all of those people can barely get enough to eat, own few personal possessions, and therefore have no way to buy a blow up boat, or much of anything else. They literally live hand to mouth. They may be uneducated, but may not be stupid, just poor, and stuck where they were born, with no chance of improvement...