As a devops manager that’s been both, it depends on the group. Ideally a devops group has a few former devs and a few former systems guys.

Honestly, the best devops teams have at least one guy that’s a liaison with IT who is primarily a systems guy but reports to both systems and devops. Why?

It gets you priority IT tickets and access while systems trusts him to do it right. He’s like the crux of every good devops team. He’s an IT hire paid for by the devops team budget as an offering in exchange for priority tickets.

But in general, you’re absolutely right.