Exactly. I use git a lot, I'm familiar with git's internals and have written a lot of git related code (our git server and all our git related infrastructure). Yet I still flinch at the idea of solving conflicts in the CLI.
I'm sure other developers feel the same, more so for less or non technical people.
So, I see you can sign into GitBook with your GitHub account. But it looks like you guys are selling your own Git hosting service. So... question... does GitBook's client work with GitHub repositories? Your site doesn't make that very clear.