The simple answer is: your kid should definitely apply.
1) To be completely honest I can't speak to the current admission climate and criteria, I enrolled in 2007 with the 5th class. Things have likely changed a lot (they do when the institute is that young and application and admission demographics change rapidly at this age).
2) Myself, I grew up in a quiet conservative Middle Eastern city (first international cohort rep!), never "made" things that I could put on a resume, and mostly just had solid grades in math/sci/compsci. I had solid SAT scores, never took the ACT, and my GPA was hard to translate (I didn't attend an AP/IB curriculum) for direct comparisons. The admissions team emphasizes that individual scores are of low relevance, as are aggregate GPAs -- Olin is primarily looking for kids who show a passion and/or aptitude in STEM/entrepreneurship which can't always be represented by scores. This is why the final stage of the admission process is a weekend-long in-person interview+team builds+campus tours where they (and you) try to evaluate whether you will survive/flourish/despise Olin's pedagogical practices, and this is ultimately the deciding factor. Parents are welcome.
3) As Olin grows older, the graduating classes have polarized more and more into founders, and pure scientists. My class ('11) had ~35% join PhD programs in everything from solar power to cancer biology, over half with prestigious grants such as NSF. And more people are becoming not only founders, but embarking on various philanthropic and/or entrepreneurial journeys, from SV startups to building solar cookers in West Africa. This is a shift away from joining Google/Microsoft/Facebook/IBM/etc, which clumped was previously the largest cohort of a graduating class (and has shrunk to ~20% now).
The hypothesis is that both these people are actually the same -- they absorb skills, look at the world, try to reason from first principles and their recently gained knowledge whether something could/should exist and improve human lives, and then just goes and does it. Pure academics is the long-term pursuit of human improvement, contributing to the greater corpus of human awareness, and entrepreneurship/makerhood is the near-term, fast-moving version. They are just essentially the same mindset applied on different timeframes.
My point is that I think you shouldn't worry about which of these perspectives he pursues at this point -- if he's the kind of kid who'll like it at Olin (he may not), the path he'll eventually take will be influenced by where he feels he can contribute the most effectively. Olin will give him some exposure to more people on the maker-side of that spectrum.