Not everybody uses git because they're infatuated with "the spirit of git". Only a tiny minority have ever even used it with the patches-by-email model it's intended for, and I would guess the vast majority of the rest have no interest in learning. People use git basically because it's what github uses, or slightly more generously because it works well when paired with a centralized host like github. The model of developing code locally and dicussion issues and patches via a web portal is the model people are taken with. Only a small portion of that is provided by git proper.