Well, I might as well jump in on this conversation. I have been skiing for pretty much my whole life (23 out of 26 years), and in that time I only wore a helmet for, oh, about a year, give or take. This was when I was in high school, by the way.
During my time as a helmet wearer, I sustained a concussion that was pretty gnarly. My memory goes away at around 7pm on Sunday, with the approx. time of hitting my head being around 7:30/8pm. Essentially, I don't regain my memory until around 8am on Tuesday morning. Not too long after that incident, I stopped wearing my helmet, partially because I didn't like it, didn't think it fit well, and I thought it looked ugly.
Many years have gone by since I stopped wearing a helmet (other than for competitions, of course), but, I can now say that I am a helmet wearer again. A week ago I went and picked up a new helmet. Not because I felt I needed the protection, but because I bought a GoPro this winter, and I can't use the chest mount when the pow is deep. Whatever my reason - I now wear a helmet.
With all this being said. I do not think Amateur and Professional skiers should be forced to wear helmets. I think this because skiers are not role models. Pro skiers are simply people who are really good at skiing. Take Max Hill for example. He smokes cigarettes, and doesn't hide it from the camera, but if he did, he wouldn't be himself. Do you want a role model or do you want a true individual? If you know what I mean.
Besides what we think as individuals, or as a community, say "we" tried to implement such a rule. How on earth would we be able to enforce such a rule/law? "freeskiing" isn't the same as other factions of our sport like ariels and moguls, it is truly an individual sport. Every competition, at all levels of the sport, across the map make all competitors where helmets. So the issues now lie with complicated issues. Who would force a pro to wear a helmet while hitting a backcountry booter, or sessioning an urban rail? Where do we even draw the line in terms of defining a "pro" and who has to abide by such a rule/law? Who is issuing said rule/law, and what would the penalty be if [enter name] was seen skiing without a helmet on.
The bottom line is simple. While this topic makes good conversation (or debate, if you will), there is absolutely no practical way of making a rule/law like this come to fruition any time in the foreseeable future. Our sport just isn't set up in such a way.