WE'RE NOT BRINGING WAILORD X SKITTY INTO THIS
Well see trainers have been trying to fly for years! Frustrated, they've tried many different methods such as copying other pokemon. This involved flailing their arms wildly, tying balloons to themselves, inhaling air and then blowing at the ground... but none were successful! The trainers became frustrated and condemned their flying pokemon to carry them as they believed that Arceus had made them flightless so they weren't super out of this world in terms of being cool. ... and that folks is why we don't fly without pokemon!
So anyway, why did I turn into a pokemon at the start of PMD?