>I'm less happy about excluding people who are coming into computing late, though.

I don't think she's doing that. Note that she doesn't say that you haven to have been programming since age 2, just that you have to have a natural interest in "solving the puzzle or building something." I came late to programming since I didn't have access to computers I could tinker with, but I was still putzing around with k'nex and getting yelled at for taking household appliances apart from a very young age.