I agree with pretty much all of this...except....your suggestion that there's no room for diversity in skiing. You have to remember that "newschool" skiing is a baby compared to skating and boarding. Skiing will diversify, niches will emerge and you'll the dominance of hip-hop, baggy shit, and hand gestures start to fade. Have patience.
You accurately described the state of skiing at the moment, but if you think it'll stay that way...well, you're just wrong.
Another difference I see is that skiing is somewhat unique in it's development. Specifically, skiing's explosion and the sharing of ideas was hyper accelerated and not at all natural thanks in large part to the internet and newschoolers.
Skating and boarding pre-date the internet and online communities. In skating, people were regionally influenced....kids looked up to local heroes, and the terrain/parks available shape the "style" of a particular scene. So, kids shredding in Oakland are going to skate and dress differently than kids in Philly. The result is that there's a huge diversity. In other words, there's no universally "cool" style.
Newschool skiing was born in the internet era pretty much, and sites like newschoolers shaped the "universal cool". So, more of a groupthink mentality exists in skiing right now. So, kids in sweden watched T Heed and T Wall, and mimicked there styles instead of whoever was killing it at their local mt. (Worth noting that those two guys mimicked Mik D...was just using an example). The result has been a homogenizing of styles.
Kids just want to be accepted and want respect...so they are afraid to take chances and think for themselves. So, that's why every superunknown edit looks like T Wall and Casabon B footy.
But....I have faith. As the industry grows and allows for skiers to have careers outside of just the typical comp skiing career (like skiers who make a living on dope film segments and photos), new and different styles will emerge. Also, the average park skier is YOUNGER than the average skater/boarder. Young kids are generally more sensitive to wanting to fit in and be accepted, thus skiers seem to be more trend whorey and whatnot. It just boils down to a lack of knowledge of self and low self-esteem. There are "old heads" in boarding and skating who have their own definition of cool, and these guys cosign new styles, making them cool.
One other thing...just bc skiers have begun to wear tight pants and adopt "that" style...it doesn't mean that it's skiers imitating snowboarders....rather, it's skiers just being themselves/being people. Not every kid that picks up a pair of skis loves Wu Tang....some kids who pick up skis like Animal Collective. Some of those kids wear scarves and denim jackets and tight pants in their day to day lives. So, yeah....snowboarding "did it first", but it's not bc boarding is inherently cooler...it's just simply that boarding is a much bigger and older sport and attracts a much more diverse rider base...for now. Soon, upcoming skiers won't feel like they have to imitate Hornbeck or some other established skier to get some recognition. I promise.