For me it's primarily a cash thing. I can't realistically set aside several hundred (or even thousand) dollars needed to travel to a scale contest in a distant location. Even a weekend trip within Japan can cost two or three hundred bucks. In my professional life, I attend perhaps one or two conferences a year. Luckily I have a research budget that covers that travel. RC is an expensive hobby. Every dollar I'd spend on travel to a scale event is a dollar I wouldnt' have to spend on RC supplies.

Second is perhaps a sense that I don't want to "play the game" of scale contests. For example, the whole documentation thing sounds like classic hoop-jumping. Ditto on the minimum viewing distant rule. In my perfect world, I'd want to let the judge crawl right into the cockpit and move the rudder pedals around. I know there are probably perfectly good reasons that the rules are the way they are. But I don't care. And I definitely don't care about learning tricks to "work the system."

And finally, I don't actually care that much about the flying part yet don't like the idea of "team scale." To me, if you're not flying a model you build with your own two hands, then you might as well be flying an ARF. And a builder who isn't also the flyer is missing some vital part of the whole experience. The sort of scale event I might enter would be judged first and foremost (and overwhelmingly) on static craftsmanship and scale/historical accuracy, for example, additional points would be offered for finding solid evidence that a three view or plan was wrong. Flying would be required (to keep model builders honest) but as long as you could take off, fly the circuit, and land in one piece, you'd get the "flight points." Sort of the opposite of what you have in pro-am style competitions, where static is just some minimum points.

For all these reason, I don't imagine I'll ever participate in a scale contest.