My 2 pence.
DevOps as a philosophy is the real deal, because apps are in the cloud, not shrink wrapped boxes. Ops are no longer guys in a closet managing enterprise backend systems, they have to manage a highly distributed application, which calls for greater collaboration between ops and dev, than before, when their scopes were separated. DevOps is simply a realization of this need.
Now comes the marketing spin, which typically boil down to misunderstanding of what DevOps is about, and misrepresents it, e.g. talking about Agile challenges and calling it DevOps. Managers read the marketing fluff, and create jobs titled "devops", as if a culture can be codified in a role. It's like having a role called "Agile" or "Quality". Personally, this drives me nuts, because I enter a job, and I am interviewed by 5 people for 5 different roles... A lot of times, DevOps is a build/release engineer, other times, it could be more Opsey, with change config tooling, scripting, and some light development. A lot of times, they embed other roles, such as DBA, architect, network engineer, etc.
Text comes the text book authors, that have no clue, and read the marketing fluff, codify it into some theoretical framework. Then new graduates come out of the system, total noob-sauce, and they either have smarts to adapt (self-learn) in the marketplace, or get thrown to the curb.
The companies that succeed do surprisingly well, become famous, their employees talk at conventions. Others that struggle, feel like a chapter out of the Phoenix Project book (by Gene Kim), but can succeed as well, because ultimately, if the company is meeting marketing/business requirements, they are making money. Thus enters a whole new field of ... drum roll... BizDevOps..