I would totally agree with that, however I have over the years developed the suspicion that people who make hiring decisions might not be operating at the same logical level that I am.
Given both that suspicion, and how they seem to behave about prominent github profiles and such, I think that being in the top 20th percentile or so on SO and a strong focus on the tags that correlate to the terms in a job announcement might be a big draw to some HR people/managers who just really don't want to mess up one more time! After the fifth complaint or so of programmers we hire don't know how to code or whatever - it might be soothing.
Given both that suspicion, and how they seem to behave about prominent github profiles and such, I think that being in the top 20th percentile or so on SO and a strong focus on the tags that correlate to the terms in a job announcement might be a big draw to some HR people/managers who just really don't want to mess up one more time! After the fifth complaint or so of programmers we hire don't know how to code or whatever - it might be soothing.