There is also a bias against enterprise developers in that most often their work is on proprietary systems, leaving no code artifacts to view on Github, which a lot of companies have started using in their recruiting process.
This has been a huge issue for me- I used to be very active on Github, but the past year or so I've been working either on proprietary systems that are internal to the company I'm at, or working on private projects that I don't want in public repos. So, if you were to look at just my Github profile, you'd see almost no activity. That doesn't mean I'm not constantly working, though!
