My question was what it means for an open-source project to be "socially punished" by not hosting on GitHub. My conclusion is that it doesn't mean much of anything in terms of actual software development, and only matters in terms of P.R. and marketing.

Some of these replies are pivoting to talk instead about the fate of abandoned projects on SourceForge. That's a great discussion, but is a DIFFERENT discussion. The parent comment talked about consequences that reduce engagement with active projects. By definition that becomes irrelevant when the projects are inactive and long abandoned.

Anyway, nothing in this lengthy post is really all that compelling. Developers didn't shift from SourceForge to GitHub because SourceForce became shady. The timeline was the other way around, SourceForce became shady because everyone left. That initial shift happened because tastes changed, people legitimately preferred what GitHub was doing interface-wise... and once a critical mass has moved, it pulls everyone else who wants the social advantages of being in the popular destination.

If GitHub turned evil (or worse yet... "uncool"), then I just don't see the migration pain you're talking about. Pushing a git repo to a new remote is trivial. Learning a new issue tracker ticket system takes about 10 minutes (they all work basically the same), and SOMEONE will write a script to automatically migrate GitHub issues to the new thing. Wiki content? Sheesh... it's just Markdown.

The biggest risk is that you've used your GitHub URL as your exclusive web presence, rather than spending $10/yr on a real domain name. But if you've made that mistake, then you'll probably make the same mistake with ANY solution that isn't self-hosted.

By all means, host your own personal open source projects wherever you like. But telling everyone else to stop doing what everyone else is doing, on the basis of some Richard Stallman-esque principles that don't hold water, seems like a waste of time and energy.