Replying to Mogul ski design

Went to the ski shop yesterday to pick up my dad's new setup and was talking with this old head about different skis. He told me that some of the dedicated mogul skiers even nowadays use straight skis, and I also was kind of confused as to why comp mogul skis are super cambered and stiff despite the fact that people tend to like a rockered and flexy tip in moguls. I really am super unfamiliar with how ski shape, profile, and stiffness affect performance in moguls, so can someone more knowledgeable than me give me some explanation?