Jeff Atwood writes about the "The Years of Experience Myth" in his usual, dead-on style:
Imagine how many brilliant software engineers companies are missing out on because they are completely obsessed with finding people who match-- exactly and to the letter-- some highly specific laundry list of skills.
Somehow, they've forgetten that what software developers do best is learn. Employers should be loooking for passionate, driven, flexible self-educators who have a proven ability to code in whatever language -- and serving them up interesting projects they can engage with.
Jeff goes on to make the point that you can use job requirements like "3-5 years of experience in such-and-such" as a baseline for determining the quality of the hiring company. If they hire based on irrelevant (or counterproductive) measures of skill, chances are good that "the rest of the team will be stooges picked for the wrong reasons."
Let's take this a few steps further.