It's entertainment/eye-candy/fantasy fun ....
To give people an real orientation to the island in the scant minutes available would just not be possible, and for the average audience that would not be entertaining anyway.
It does create some positive energy about Belize and I have heard from a lot of long-lost relatives who wonder if I ever wear shoes.
The crew from HGTV I worked with was super-nice - they must have passed a test in patience, positive thinking and good manners before being hired.

It's great that they keep coming back!