Well even with just one person committing, you'd still have a remote. Even for personal stuff that you don't want to publish, you can still use BitBucket private repos (or bare repos on any server you have access to).
To be honest, backups wasn't what was first in my mind when answering that question (backups are a separate system in my mind), it was that being able to "git diff" to the last time it was working is often all you need to do to get your head round why it's not working now.
IMO losing a project from an inexperienced developer that isn't yet integrated is a lesser problem than getting that project with no history and whole lot of random debugging experiments that went on long enough that they couldn't be reversed in an editor's undo.
Them: how many people have to work on a project before version control should be used?
Me: Uh, one? Git init is the first thing you do after naming the directory.
Them: audible relief
One wonders what they have seen.