I think that it helps more than it hurts. I believe that it is crucial for people to see these beautiful, undisturbed environments to really understand what is at stake. The downside could be that these tours themselves cause too many people to come into the environment and the areas might start to get built up to cater to the tourists.
Ecotourists who follow the outdoorsperson's code absolutely help the environment. Ecotourism creates activists who see the natural beauty of our planet and feel compelled to help save it by embracing green energy, buying green products and eating organic food grown locally. Ecotourism works by inspiring humans to do better when it comes to take care of the planet that takes care of us.