Speaking from my own experience, the truly amazing ultra-productive programmers often come with the caveat that they don't spend much if any time mentoring, explaining, or sharing how they work and why. They can produce a patch in two minutes, or interactively fix up some corrupted data in a few seconds. But spending the time to demonstrate to everyone else how they did it so that the other members of the team could learn their own product better would take a lot more of their time. They're always the ones to fix the unexpected problems, because they can figure it out and fix it before anyone else can even get a handle on what's wrong. That's great in the moment of crisis, but in the long run it can be devestatingly counterproductive.
So whether intentionally, tempermentally, just due to the constant demand for their services, or just because it's tautological, the 10x programmers don't actually contribute back to their team's knowledge, which means the rest of the team stays at 1x, and whent he 10x programmer moves on to another project or company, the rest of the team flounders around while they have to figure out all the things the 10x programmer never bothered to share.
I would agree with you on this if you were to state that someone looked at the code created by one of these ultra-productive developers, asked questions, and was told "f* off".
But, did any of the other developers even look at what the other ultra-productive developer did ? Did it get studied in detail, and were questions asked of the ultra-productive developer ?
I've been the ultra-productive developer in such a situation before. After a couple of runs of "hey, here's some cool things that I did that I thought you might be interested in" followed by a lot of glazed-over looks and shifting in seats, I got the message and stopped doing them. There simply was not any interest, and I learned a valuable lesson: most developers don't have any where near the same level of interest in the craft as those that have done it for 25-30 years and are passionate about it. It's just the way it is, and no amount of persuasion or pleading is going to change it.
Either that, or I'm mind-numbingly boring and that was the reason... ;-)
So whether intentionally, tempermentally, just due to the constant demand for their services, or just because it's tautological, the 10x programmers don't actually contribute back to their team's knowledge, which means the rest of the team stays at 1x, and whent he 10x programmer moves on to another project or company, the rest of the team flounders around while they have to figure out all the things the 10x programmer never bothered to share.