I think I agree with your argument, directionally, but in the case of the C++ hacker, might it be the case that he needed to find a different role, job, and/or manager to really leverage the power of a 98%tile C++ programmer?
That's a legit option and actually that's what happened with this guy - we moved him to a parser team from a client-facing team. But we both recognized that as a bit of "defeat" - we failed to improve his communication, so as plan B how do we help him not get fired.
The point I am making and that I don't want to get lost is: there's a huge difference between "I am consciously choosing to be a C++ hacker" vs "I am falling into this bucket because I fear doing other stuff". First one is fine, second one means a person is under-living their potential.
Why is that a defeat? Did he think he was good with people, or want to interact with clients? Or at your company was the parser team a professional dead-end or something?
First, are you living your own best life? If you ask him "do you want to be limited by comms skills for the rest of your life, in all the ways it affects you and home and at work" he's say "no, I'd rather not have this problem" but then we couldn't really get it to change. So he fell short of his own recognition of what his life could be.
Second, it just limits you. There's nothing wrong with writing parsers and someone has to do that, but there's a difference between "choosing" that and "being limited to it." Versatility and capability is important. Say he wanted to go work somewhere else, the more skills and versatility you have, the more options you have.
Third, even within such a job you're still limited. EG: are you having a technical debate on your team? The better you can communicate, the more likely you are to advocate well for your solution, the more likely your good ideas will materialize, etc.
The point I am making and that I don't want to get lost is: there's a huge difference between "I am consciously choosing to be a C++ hacker" vs "I am falling into this bucket because I fear doing other stuff". First one is fine, second one means a person is under-living their potential.