Not very true about the wildlife. Have you been heli skiing before? The majority of the time you are quite high in the mountains, not to mention that it's winter and there really isn't much active wildlife high in the mountains during the winter. The effect of heli skiing doesn't extend into the summer on wildlife. Maybe a few small pieces of dropped lunch garbage or a lost ski. Ski resorts however, cut trails through habitats and destroy plenty of areas that wildlife would use in the summer. And although wildlife will inhabit these areas, it's in a different way than if it would be left alone. Sledders generally access the higher elevations via cutblocks and trails/access roads, so they aren't further disturbing the environment for the most part. They also will generally not leave a lasting impact on the environment below the snow.
On the topic of fuel consumption; when I went heli skiing it was in an A-star. This type of heli uses approx 190L of fuel per hour. Per skier that is 19L fuel per hour flying time. BUT our heli serviced 3 skier groups of 10 people each, so it's about 6.3L per hour. But there are also 2 guides per group as well, so it's about 5.2L of fuel per skier per hour of flying time. On a standard heli trip you only get 3 runs unless you pay for unlimited vert. Let's say you did what we did and skied from about 9:30am to 3pm. 5 1/2 hours. The heli is not in the air the whole time as you stop for lunch and such, but for arguments sake let's say it was. Per person you used 27.5L of fuel, or for US about 7.25 gallons.
Do you honestly believe that this amount of fuel is statistically more significant than the amount used to travel to the hill plus the amount used to power the chairlifts?
I'm all for protecting the environment, being conscious of energy use and trying to live life more sustainably. After doing heli once, I won't go again until I can do a trip to Alaska because the terrain was just too tame for me. Until that point, I plan on going to touring lodges like GAH because they have amazing terrain and it's up to you about what you ski, which is good for sending lines but a bit more nerve racking because I don't get to practice avy safety much living out east.
However, if you plan on making an argument saying that the sledders, cat skiers, and heli skiers are ruining the environment, at least try to make it valid.
Sorry for the long read folks.