enjoyed reading this post, and the conclusion (that people hire people like themselves) certainly seems supported by the premises. But it's not an obvious conclusion; indeed, if i would have assume the opposite was true--ie, that people hire their natural complements. This is certainly true for me, because i (and i assume others as well) have a natural tendency to undervalue the skills we have and our memories tend to have a downward bias when estimating/remembering how many hours it took to learn a certain skill (e.g., a new language, new library, etc.)--ie, the silly misperception that something can't be heard to learn if we already know it. On the other hand, i tend to value highly those skills i would like to learn but haven't--either haven't yet found the time, or i have made a couple of cursory attempts and set it aside for another time. To me those skills are naturally "hard" and if they are relevant to the work that my team does, then i value persons with those skills very highly.
This view might not be widely held; it's also possible that it's not in conflict with the view expressed in the OP, which might be directed more towards personality rather than skill set.