If you doubt this then you are probably in a completely different industry than I am. I cannot prove it to you except by my own experiences with managers and salary recommendations.
This seems highly dependent on which kinds of software companies you are talking about. I hire lots of developers and I have never looked at anyone's github profile. Also, I don't recall any candidate asking me to look at their profile. I have seen a few resumes that have included one, but not very many - and I look at a lot of resumes.
I'm not making any judgement about the value of the profile, but in my corner of the world it doesn't seem very important or even common.
I'm not making any judgement about the value of the profile, but in my corner of the world it doesn't seem very important or even common.