Not true. Github only hosts projects publicly for people who want to host their project publicly.

They don't have a mantra of all information wants to be free, and indeed their entire business model relies on hosting private repos.

I understand people wanting to host their open source on a server that's also open source. There's an argument it makes business sense if the closed source setup creates a long-term drift to GitLab or elsewhere. Nevertheless, I don't see the closed source as a contradiction.

You can love open source while producing a mix of open and closed source. Building a sustainable business often means being selective about it and seeing open source as a tool you can benefit from (enlightened self-interest), rather than an ideology you must adhere to at all times.

A hint of irony? It's freaking absurd. The "hub" for decentralized git (The "D" in DVCS stands for Distributed, doesn't it?) which has become the Kleenex of open source, is itself a closed, proprietary system. It's beyond ironic and well into oxymoronical. And then MS bought them! You can't make this stuff up.