Your insight is actually backed by one of the best, most world-reknown programmers alive: Steve McConnell. On page 832 of Code Complete 2, one of the world’s most acclaimed software engineering book, McConnell says:
People also put an absurd emphasis on the amount of experience programmers have. “We want a programmer with five years of C programming experience” is a silly statement. If a programmer hasn’t learned C after a year or two, the next three years won’t make much difference. This kind of “experience” has little relationship to performance.
Yet the job descriptions are apparently an HR contest rather than a true skill search.