I think there's a key distinction here between "unprofessional" traits that can enhance productivity, vs. unprofessional traits that kill productivity.

I agree that the former are good things and should be preserved where possible. (And not just in technology companies; some time ago I remember reading about a study that looked at various heavy industrial companies--auto manufacturers were one type--and found that the most productive ones were the ones that had many of the things you cite: limited or no dress code, limited HR involvement, limited written work descriptions and a lot of autonomy given to workers.)

However, the Github case appears to be an example of the latter. I don't think that's something to be celebrated.