Any developer can tell you that not all C or PHP or Java programmers are created equal; some are vastly more productive or creative. However, unless or until there is a way to explicitly demonstrate the productivity differential between a good programmer and a mediocre one, inexperienced or nontechnical hiring managers tend to look at resumes with an eye for youth, under the "more bang for the buck" theory. Cheaper young 'uns will work longer hours and produce more code. The very concept of viewing experience as an asset for raising productivity is a nonfactor — much to the detriment of the developer workplace.
"Protozoa are small, and bacteria are small, but viruses are smaller than the both put together."