JC,
My understanding of the geological situation in SE Florida is that the Turnpike is sort of the line of demarcation for real solid ground and that areas west of it are mostly the swamps you refer to.
Early community golf course development seems to have occured along the following lines.
Fairways were crafted from the material from dredged out lakes, giving the homeowner views of lagoons and golfers fairways to play on.
Thus, your description is pretty accurate in many, many cases where the subsoil conditions weren't the greatest.
When you're landing from the west at Palm Beach, Ft Lauderdale or Miami you can see course after course in that mold.
But, while they may represent the majority, there are quality courses that don't have that configuration or look.