A bit harsh on Goa and Gambia.Obviously they don't suit DMW,so maybe they aren't for him.
A lot of people enjoy these two destinations especially if its their first visit to new continents and a chance of seeing some different birds.
As you say, both are convenient, which helps, if like a lot of people, they are working hard all year and just want to jet of somewhere, relax in a comfortable hotel and see some lifers without having to put in a lot of effort.