Most of experienced developers have become project managers since or IT directors. Back then, about 20 years ago, those methodologies such as Agile Software Development didn't even exist, and they were able to produce and to deliver working systems.
These same guys might lack the knowledge of such proposed practice from these new methodologies resulting of some sort of resistance against bringing forward those approach.
We cannot be rough at them for so, they only resist to changes they don'T know or even understand, just like let's say a customer who is used to work one way, and then we come with our new methods and then change this customer's habits within a day! It's quite normal that these resistances occur, they're human bahviours.
Furthermore, for some of these more experienced-guys, they don't just don't get the point of working in pair, for example. Just like they generally don't believe in scrum meetings, they prefer the old-school way, which has known its success in some way, of a meeting lasting from 1 to 2 hours a week.
As for administrators, those responsible for the budgets of programming resources, it is seen, as for pair programming, to pay a programmer doing nothing while this doing-nothing-programmer could work on another part of code to multiply productivity. You cannot really blame them neither, as what they think makes full of sense.
Some suggestions from the Agile Software Development are easier to get the benefit from in comparison to some others. While pair programming might not know a real success in practice, or even daily scrum meetings, what is a success though, in my experience, is beginning coding as soon as we get a precise enough sketch of the software, its requirements and features, never to forget the priorities given from the customer himself. Then, updating the UML analysis while developing for an iteration.
Software iterations, in my experience, begin a growing success.
Let it time, Agile Software Development, such as Test Driven Development, well in my region, are still new stuff. Once they will get more practitioners, their practiced practices will grow with it, I believe.