He might know how to write code, but obliviousness towards source control (and backups, for that matter) is a HUGE indicator of him not being a professional.
I would agree. User friendliness isn't a bad goal for any piece of software, but there is a certain level of knowledge we can expect from a professional. Knowledge of their chosen tooling is one of them I feel.
It's not even knowledge of tooling, it's knowledge of practices. How would you feel about an electrician who doesn't properly ground the circuit he's about to work on? That's how I feel about a programmer who doesn't take backups of his code in short intervals (which is a big part of what VCSs do).