Ecotourism - Agroforestry - Kandyan Homegardens

How can ecotourism be described? Eco travel is it only a marketing slogan? Often eco tourism is understood as touristic activites close to nature or natural habitats. But is not exactly this kind of tourism particularily destructive?
Take Sri Lanka for example, should we go to Sinharaja? Should we merely protect certain habitats and leave other to be distroyed? I think "NO", however, looking at demography and travel worldwide the only way to protect biodiversity may be anthropogenic but nature like habitats. Kandyan homegardens are something close to this (in certain aspects at least), although densely populated the area is full of small agroforestry like structures (see image, which from a crop like perspective represents more african species than east asian...).

These systems are often also characterized by living fences and the like. Due to the different canopies many trophic levels of insects, animals and plants can dwell. Clearly an increase in biodiversity. But what has this do to with tourism? Consult the main points for little impact travelling. There are other interpretations of ecotourism which do not focus on "close to nature" but compensate your impact while travelling....