I am gradually coming to the opinion that many 10X developers really do end up being compensated fairly, but it rarely happens while they are still in the "developer" box.
It doesn't necessarily just happen from taking on extra risk, either, though starting your own company is one way to do it. Personal anecdote (I'm not a 10X developer but I know a few things about a few things): I previously built CRUD apps and made $X, and I turned down a few offers this year to build CRUD apps for [6 * $X, 10 * $X]. The big thing that changed? Improvement in marketing myself and better selection of CRUD app genre. (A/B testing isn't any harder technically than building university registration systems... it is just worth orders of magnitude more revenue.)
That was one of the things that really surprised me about the real world: that big advancement only comes from big lateral jumps. Different companies, different projects, different markets, or different customers.
There's this model of the world we're taught as schoolkids - at least where I grew up - where you work hard at something, do as your told, and slowly but surely you rise up. And maybe at one level it's true, but it's very slow, and you'll never become the sort of success you read about in the paper that way.
Instead, I've found that what usually happens is that you join an organization because you meet some minimum skill baseline that they're looking for. And then as you practice and learn from the people around you, you end up picking up a bunch of other skills and getting better at your job. But the people around you generally won't notice. First impressions usually pigeonhole you into a general category, and then people are blind to gradual changes.
So to reap the rewards of everything you've learned, you have to expose yourself to new people. Jump ship, and suddenly you seem really valuable to them, because all those skills you've picked up which your current organization takes for granted are new and useful.
There's a leverage effect as well: people try to work with others of roughly the same level. If you're diligent about practicing, you'll go from being (hopefully) near the bottom of your team to the top of it. If you then repeat the process, your new teammates better be higher skilled still, and so your team as a whole can tackle more ambitious problems.
Unfortunately, it also works the other way: somebody works in a company until they recognize how useless that person is, and before he or she gets fired they jump ship to a new company where they are greeted with open arms as the new guy/gal that will fix everything. Lather, rinse, repeat. If they are smart they use the same argument you made to actually rise in the corporate hierarchy with each step. This allows them to beat the Peter principle and rise above their level of incompetence, leading us to totally incompetent people at the top of the hierarchy.
So if you see somebody who changed jobs every couple years, be careful.
We might get paid double what they do, but not 3x or 4x. Or maybe I'm not that good ;)