I think this perception is due that if you are hiring someone with experience in software, you already perform a selection on who will apply, you'll typically get people with "some" technical skills so the people you'll see with people skills are the ones with some intersection of both.
Also good technical skills aren't that easy to discriminate in the length of an interview. Its much easier to discriminate people skills since you are putting people in a stressful situation that is all about dealing with people.
Finally, a lot of the people with both technical skills and some people skills will avoid widget factories type of environments. If they started out of college, they probably got a programming job in a widget place, their perspective is the lowly ranked employee, its unlikely they appreciated the experience in comparison. Once they found a more enjoyable position, they probably won't go back to that type of environment. They won't even apply.
I disagree emphatically. Good people skills are far more common than good technical skills. However, it is incredibly rare to find someone with both the technical skill and the people skill to be a technical manager.
people skills = easy to find
technology skills = more difficult to find
technology skills + people skills = incredibly tough to find
If you talk to people who hire/interview and manage people as their primary role, you will often hear them say that the candidates attitude/people skills is more important than their technical ability.
If the candidate has good attitude/people skills, they can be taught (or will pick up on their own) good technical skills. But if they only have good technical skills, but lack a good attitude, that is something that is very difficult to teach/improve.