Value of ideas is massively overstated in biz school lit, imo... Ideas are fine, but it takes a lot of work to prove that one actually works, and then a lot more work to bring it to production.

All of the work involved needs financial and material support to happen. It's easy to have an armchair idea, but to put a hundred+ hours into the very first realization is extremely difficult if it's not your day job. (And repeat for the thousands(?) of hours necessary for bringing to market...)

In my most anti-elitist frame of mind, I expect there's a mismatch between who has good ideas and who has time to prove things out... Elite business schools are populated (on average) by walking Dunning-Krueger effects, powered by trust funds and lack of consequences: of course they have a shortage of good ideas... Meanwhile people with the actual experience and expertise to produce good ideas have day jobs to keep them from executing.