I am of two minds on the subject. I love that there is enough interest in tartan and in Scottish culture that people would go to the trouble to design a tartan from scratch. I would love to have a tartan registered for my bank or other companies.

I am also aware that most of our set tartans come from Wilson's of Bannockburn, so tartans were, in some instances, made up and lent credibility by clan chiefs some of whom knew as much about their traditional tatans (if any) as a fat Hanoverian.

I think it stretches credulity to think the rules that are so often espoused here and by other "authorities" on highland dress, would have mattered to the Highland clansman whom we are emulating in our dress. These tough fierce individuals, who lived in a hard, desolate land, fending for themselves against man and beast,this Highlander,if he didn't like a particular color or line in a tartan, I doubt that he would have let rules of tartan or dress codes bind him, he might have even worn a fur sporran in the day. If he was a MacDonald highlander liked yellow better than red, you can bet he would get what he wanted and laugh at anyone who told him he broke the tartan rules.
So if someone wants their own unique tartan or customized traditional tartan, how does it hurt us?
However
The people who wear a one off, Tony Hawk tartan will never be "in a clan." They will walk around a games and may look great and have fun, but there will be no one else with their tartan, no camaraderie with the their other clansmen. They won't have the thrill of their clan tartan jumping out at them from someone in the crowd. They will be participating in a thing which today is about connecting, forging bonds, enjoying the company of an extended family....and they will be alone. They may have the enjoyment of the tartan itself, but not what it embodies. They are, metaphorically, bodies without souls...we should feel sorry.