Except then it's not DevOps. If you have people working on 'DevOps' 100% of the time, that means they aren't working on Dev, and are only working on Ops.

The idea behind DevOps is that Dev(elopers) do their own Op(eration)s, rather than throwing stuff over the wall for a separate team to manage.

Not only has the industry done the opposite in many cases, they kept the name DevOps, meanwhile the full time operations staff have over complicated deployments and builds to the point that even they don't understand how they work anymore.