Technology has changed a lot in the past 30 years, and the tuning skills we now need don't reside in the heads of individual programmers anymore.
2009 will mark the 40th anniversary of my first IT-related paycheck. When I started, much of the technology was pretty new, and every kind of capacity was scarce. So code optimization was an essential part of the development and test cycle for virtually all the software we wrote. We had to focus on memory footprint, context switching and execution path length because the targeted machines had relatively little memory, very slow direct-access storage and relatively slow processors.
This took a lot of work, specialized skills and time. As processors became faster, memory sizes grew larger and disk-drive performance improved, developers tended to rely more and more on the compilers they used to get the optimizations right. Tuning skills atrophied. Speed to market came to matter more than efficient code. Moore's Law seemingly eliminated the need for tuning skills.
Continued at CIO Insight.