Now that I think of it, that's maybe not a terribly bad idea for some open source projects in which I want a little friction to submitting patches. (Because, for those projects, I actually dislike patches. It's usually more work for me to review for design and code quality than to make the changes myself, if they were good changes at all).
And there's the mess when people are driven by email notifications for Git repo changes/events that they then access in a Web UI. It's great for wasting people's time, and people also end up with piles of Git repo emails that they casually archive/delete, potentially missing things, due to DRY violation and because there's more steps between looking at the email and going to the Web UI to handle things.
But when you just want random people to be able to log into a Web site and interact with whatever computer-mediated workflow there, telling people to use old-school email is maybe counterproductive.
