An excellent reason for planting coconut trees is their extensive root system and what that root system does to stabilize the environment. The trees are lost sometimes: a poor start that didn't allow the root system to get a good grasp at the tree's beginning; years of people hacking at them with machetes; encroaching seas that wipe out what the roots hold onto.
Here's one that got a bad start and then was chopped at for years. Planted just to the right of the trunk are two small plugs of a grass that may help this (see May 16, 2013 post about the grass).
But none of them give up easily.
Photo by Andre Shank