I think it is just different priorities and skill sets. Skiers that only ski park are solely focused on learning tricks and therefore ignore the actual skiing skills that you learn from skiing moguls/racing/backcountry. In the same way mogulers, racers, and big mountain skier have no interest in the technical rail and jumping abilities that Park is focused on. So both groups have their own standards of what makes a good skier and are thus in conflict about what skiing is about. I personally think that being a well-rounded skier is the true measure of a skier. You can be a good park skier and completely suck at actually skiing, but you can also be a big mountain skier and have no ability in the park. I think both of these extremes are not optimal because you leave out some amazing experiences. Park skiing is super fun and progressing trick-wise is a blast, but it doesn't have the sense of adventure and exploration that backcountry skiing does. Plus anyone who says they don't like powder either has never skied deep pow or isn't a good enough skier to ski it. So I agree with what people said above, just do what you like and don't hate on others, but I think better advice is to just do everything. Don't trap yourself in a box of being a park skier or a backcountry skier, you can have so much fun doing everything that it is a shame to limit yourself to one aspect of skiing.