your last: - 'you can strive to be unique in a one-person class that is more immediately profitable and scalable than a commodity programmer.' seriously?
if this guy wants to become an expert in the technologies he mentioned then why is that so wrong? if he enjoys programming and has the drive to get to the top then he should absolutely go for it. smart employers are going to appreciate and see value in someone that has spent thousands of hours coding.
You'll get better work on better terms if you focus on results rather than tools, even if your technical skillset is fundamentally the same as another dev with a poorer sales pitch. You're finding the best mutually beneficial business arrangements out there rather than just pursuing a predefined career track.
Edit: Mastery is its own reward. If you want to become an expert at a particular corner of technology, go ahead. Just remember to explain your work to others in terms that aren't unnecessarily limiting.
Senior C++ Programmer jobs.
And what do you think they'll have to prove to potential employers? That they are capable of writing lots of C++.
Commodity programming is an inefficient use of this person's time and luckily he will be known and respected by enough business leaders to be able to carve out a more valuable (and again, mutually beneficial) arrangement somewhere in the Valley.
This job may involve C++ but it won't be as generic as you described. Think Paul and Bret at FriendFeed. "Python Programmers" was not their $50 million value proposition.