In 2002 Scott Ambler observed in Agile Modeling (p.4) the typical career path of a corporate developer:
"I also believe that the way that developers learn their trade has a few unique dysfunctions. For the most part our colleges and universities are doing a reasonable job of educating developers for entry-level jobs. However, even if the schools were doing a perfect job and everyone was getting a degree or diploma, I suspect that we’d still have a problem due to the inherent nature of software developers. When software developers are young, in their teens or early twenties, they typically focus on learning and working with technology. They describe themselves as PERL programmers, Linux experts, Enterprise JavaBeans (EJB) developers, or .NET developers. To them technology is the important thing. Because technology is constantly changing, younger developers have the tendency to just barely learn a technology, apply it on one or two projects, and then start over again learning a new technology or the latest incarnation of what they worked with previously. The problem is that they keep learning the same different flavors of the same low level, fundamental skills over and over again."
"Luckily, many developers become aware of this after several rounds of technologies - once you’ve written code for transaction control in COBOL, Java, and C#, you start to realize that the fundamentals don’t change. The same is true of database access in various environments, user interface design, and so on. Before long, developers begin to realize that many of the fundamentals, which they may or may not have been taught in school, remain the same regardless of the technology. This realization often comes when they reach their late twenties or early thirties, typically the time when people start to settle down, get married, and buy a house. This is fortuitous because these new demands mean that developers can no longer afford to invest vast amounts of time learning new technologies; instead, they want to spend that time with their families. Suddenly higher-level roles such as project lead, project-manager, and (non-agile) modeler become attractive to them because these roles don’t require the constant and intensive effort needed to learn new technologies. So, by the time that developers begin to truly learn their craft they’re in the process of transitioning out of their roles as developers. Luckily, new “young punks” come along and the cycle repeats itself. The end result is that the majority of people actively developing software are typically not the ones best qualified to do it, and they don’t even know it."