The problem that others are having with DevOps is that they seem to be defining it differently than you are. What you wrote makes sense but the scenarios people are complaining about don't sound at all like your definition.
That's part of the problem, yes. DevOps started off with reasonably laudable goals: to promote a methodology whereby development teams and operational teams were tightly integrated in a way that made operational and deployment issues part of the development process: development would be driven by the need to deploy useful functionality, not just create it. That way, you didn't have a discontinuity where things were programmed, then someone would have to figure out how to actually deliver that bunch of code.
The problem which the author of the article references is that this often gets perverted from the original laudable idea of teams of developers and operations people working together, to requiring every single DevOps person being equally qualified to do everything, and then from there pushed even further to many companies creating DevOps positions where those DevOps people are literally doing everything, and not just knowledgeable at those things.
There is no question that a programmer that understands SQL or database architecture or storage systems or high performance networking or internetworking or virtual hypervisors is a more valuable programmer. They can use that knowledge to guide their development, write better code, and communicate better with the actual DBAs and network engineers and sysops and hypervisor admins. But when management types start to think that the best way to do things is to hire DevOps qualified people to just randomly do everything without any focus or specialization, that's when the myth of DevOps overtakes the reality of DevOps and begins to create real problems.
I don't honestly know to what degree that is pervasive in the industry: I haven't seen too many examples of it myself outside of certain high profile ones (the author mentions Facebook). If it is trending upward, I think its a bad trend. But to the extent that I see companies use DevOps correctly, as the glue-people to interconnect individual development, operational/deployment, and quality assurance teams, I think its a positive. But I agree with the article author that actually *replacing* developers, QA people, and operational people with DevOps people universally would be a Bad Thing. I just don't know if its actually really happening