Ya it... takes a while to accept the scoring system. There's very few formal rules to how the scoring works because culturally that's how those sports evolved, there's been attempts to formalize it and it's always universally panned by the athletes. Each judge and judging panels have their own criteria, too, so there is inconsistencies from competition to competition (at the Olympics in snowboarding they seem to always heavily reward weird, rarely used lines), and feedback from the athletes themselves also affect that. But general rules is that the hardest run that looked easy and smooth wins. The big complication that is hard to wrap your head around even after watching a while is that "hardest" doesn't always means most spins or flips.