Here's what 9 out of 10 skiers are capable of doing in regards to filming/editing input:
"You know that one shot in that one ski movie where blahblahblah....let's do that".
A skier and/or fan of ski flicks will draw on what they've already seen in the context of a ski movie, and best case scenario, will be able to recreate that in their own project. A gifted/talented filmmaker will draw on other inspirations and will most likely be adept at translating an idea for a shot into an actual shot. That takes practice, and for the most part, if you're good enough to be in front of the camera, you've invested your time in skiing and not filmmaking. (If someone says, "What about Pollard and Clarke, no0bz?!", they're exceptions, not rules.)
The difference between a skier with a camera, editing software, a logo, and a fanbase and a filmer/editor is huge.
It's like anything...a filmer is "good" for two reasons: 1.) He probably has some natural aptitude for it. and 2.) He spends a ridiculous amount of time behind a lens and he knows how a particular shot/angle will look on a monitor ,and more, he knows how that angle/shot will fit with the other angles/shots he already has or plans to get.
Run on sentences aside, it's arrogant and ridiculous to think that being good at skiing equates to being good at making ski movies.
Can collaboration between an editor and a rider be a good thing? Yes, of course it can, but in the overwhelming majority of cases, better to let the filmer/editor do their thing. Unless of course you want filmers collabing with skiers on the skiing. I can totally see Drew Lederer helping Simon stomp a superman dub...