No employer has ever asked me for a github address, or a list of open source commits. I put github on my CV via a goo.gl url last time, and counted very few visits. Yet they invited me for interview.
HR filter by qualifications, and hiring managers filter before phone screen on what you claim in your CV. Then they assess at the interview whether you were lieing.
If you were genuinely famous in the OS community, or had spent a year full time making an amazing product they could see, I think things would be different. For most software engineers, 80% of our work is for our employer. I've made some awesome stuff for other people. It's not on github. My boss wouldn't like that.
Is the above really a good recommendation? I'd say at least the MS would get him through the HR filter?
Then after that, HR appear to filter by previous job title, hoping to see career progression and a similar title previously.
I guess the people at a large company that reduce 200 resumes down to 20, before the hiring mangers sees them, do not understand Ruby. They understand that they must be able to quantify why they rejected an applicant in case of a lawsuit. Hence the frustrating rigidness.