Because DevOps also include things like Agile, Lean, MVP, avoiding local optimisation, minimizing the amount of work in progress, and many other things. DevOp

Because DevOps also include things like Agile, Lean, MVP, avoiding local optimisation, minimizing the amount of work in progress, and many other things. DevOps is not just about infrastructure, you need buy in and a change of mindset (compared to waterfall) from the Devs, QAs, PMs and even sales / upper management. This is really a company-wide change aka culture. So unless you are the one putting all of this in place, "DevOps engineer" doesn't really make sense. Automation engineer is what most "DevOps engineer" really are: automating as much as possible everything that touches the infra.