Opinion:
Thats one heckuva generalization. In terms of clothing, style, trick selection, equipment, and even edits new wave and old school are hella different, ski how you want-sure. Saying they're the same because "It's all skiing" is stupid- what about racing, telemarking, or touring? are they all the same because "iT's alL skIiNg"? or hell we should just clump cross country in there too cause I guess that's skiing too.
Opinion:
There are many differences in skiing with its many styles and disciplines. People who throw out the "hey guys it's all just skiing,chill" just don't want to form an opinion or are too afraid of upsetting people. Ski however you want, please, but saying it's all the same because you're sliding down the hill on skis is dumb.