Skateboard filming sucks because it's just too easy to pick up a DV camera and go film. In snow sports, there's a process that includes tons of setting up, so the filmer may as well just try to make the shots nice while people build jumps, set up rails, etc.
Also, skating is way more tech, so it's boring for the filmer to do the same pan-in pan-out switch the focus kind of stuff while some skater tries ninety-five times to fakie flip sixty stairs. Snow sports take way less tries to nail shots. Especially in the backcountry.
Finally, you can't skate anywhere anymore, so there's no time to set up floodlights and flashes before a cop's giving you a ticket.
On an unrelated note, I only saw MJ's part (it's on the internet, don't tell mom). He found a nice balance between sick creative stuff and mind-boggling tech stuff.