I think both of you are respectively overestimating and underestimating the significance of GitHub.
Are there a lot of projects that use Git without a hosting intermediary because of genuine advantages? Yes, absolutely. Plenty of core infrastructure and applications, many of which significantly predate Git or GitHub.
Is there a growing subculture of people who essentially equate Git with GitHub and end up completely subverting the "D" in DVCS, incurring unnecessary downtime and who pretend Git/GitHub are the be-all-end-all? Also yes, with circles such as those of HN being overrepresented with "GitHub is your resume" rhetoric and various startups or hip SaaS having GitHub be their single point of failure.
Being the #1 software hosting site in the world does have an effect on demographics, at the end of the day. By now Git and GitHub have an essential, if controversial relationship.
Back when I followed the long discussions about introducing git at the ASF (now live at git.apache.org) several git proponents said that git without github is pointless to them. I was quite surprised how adamant some people were about that. Before then I never thought of github as a sort of GUI for git, just as... one service for repository storage out of many, I guess?
The ASF has a strict policy of self-hosting. So git repos are now mirrored to github from ASF intrastructure, for the github fans who initially suggested the reverse (ignoring obvious problems such as ASF having no influence over what happens at github).
Are there a lot of projects that use Git without a hosting intermediary because of genuine advantages? Yes, absolutely. Plenty of core infrastructure and applications, many of which significantly predate Git or GitHub.
Is there a growing subculture of people who essentially equate Git with GitHub and end up completely subverting the "D" in DVCS, incurring unnecessary downtime and who pretend Git/GitHub are the be-all-end-all? Also yes, with circles such as those of HN being overrepresented with "GitHub is your resume" rhetoric and various startups or hip SaaS having GitHub be their single point of failure.
Being the #1 software hosting site in the world does have an effect on demographics, at the end of the day. By now Git and GitHub have an essential, if controversial relationship.