What if you are an accomplished skier? Is going to a South American resort really what you're looking for? If you've skied in places like Jackson Hole, Lake Tahoe, Chamonix, Whistler-Blackcomb, is going to a tiny area with slow lifts and variable conditions really satisfying? Sure, it's better than NOT skiing, which is your option in the northern hemisphere in August and September; and I think a lot of people rationalize it this way.
Why not go to Chile to do something you can't do in the northern winter? Ski into a crater of a volcano (and come back out); ride a horse through a forest to get to the snow; make a first descent; tree ski through 3000-year old trees; totally escape the modern world; follow a dirt road past the markings on a map. These are the experiences that bring me to Chile year after year, and these are the experiences that I live to share with others.
I think a lot of people say, "I want to ski in Chile." Then they look at the time and financial commitment and they realize, "Jeez, US$4000-plus per person for a week at a resort (including airfare), without a guide or wine. That's as much as... a week in Japan; a season in Colorado; a good amount of heli-skiing; a month in Europe..." And to this I say, "yup." If you compare apples to apples, resort experience to resort experience, it's, well... August.
Don't go to Chile looking for the experience you know and love at home. Go for something new. Go to do something you've never done before. It is this opportunity that makes this place so special.