Life-long learner who happens to know a little about writing software.
Disclaimer: anything I post here is representative of my views, not necessarily those of my employer
I've always said that DevOps is the natural progression of Agile. When we are doing waterfall, the rate of change being introduced is relatively low and the dynamics of the Development and Operations teams kind of works. Certainly, there are still the issues you point out above, but the interactions are fewer and therefore more manageable. When a company starts to embrace Agile, the pace at which Development teams attempt to push code into Production environment increases which makes the issues amplify. This is where I believe DevOps comes in.
I've always said that DevOps is the natural progression of Agile. When we are doing waterfall, the rate of change being introduced is relatively low and the dynamics of the Development and Operations teams kind of works. Certainly, there are still the issues you point out above, but the interactions are fewer and therefore more manageable. When a company starts to embrace Agile, the pace at which Development teams attempt to push code into Production environment increases which makes the issues amplify. This is where I believe DevOps comes in.
Agile is the Why, DevOps is the How... :)