I struggle with the idea of tourism being a good basis for an economy. At some point you reach a level where the appeal is outweighed by crowding, and the experiences people want are no longer available.
From a sustainability point of view though 10,000 people concentrated in a single tourist complex is better than 100 villages with 100 people each.
It's 2.2 million local residents living a long term largely sustainable life that are being swamped by an additional non resident 13.9 million people per annum.