I wouldn't throw your article out - we certainly didn't disprove it as a methodology, but there are some business impacts that need to be planned for ahead of time.

At Yahoo! we tried this on a few projects and ended up calling it waterscrum. Wanting the dev flexibility of agile and the (perceived) business certainty of waterfall at the same time isn't really possible when it's not understood that the dev methodology has impacts outside of the tech organization. If you're doing agile dev, the marketing materials, sales collateral, etc are much more difficult to write and lock down when you're looking to make a splash in the market. For agile to work the entire company needs to be okay with some level of uncertainty, or at least understand that for major market releases you still need to plan a date far in advance. Just because you're launching code doesn't mean you're launching a product, and getting materials locked down is harder to do when, by definition, changes happen more frequently.

School systems don't sacrifice the best to help the worst. Sacrificing the minority to help the majority is a more accurate description. If a uniform approach to education is to be taken, this is likely the best strategy for society.

I don't believe we should have a uniform approach for every student, but I also don't think a unique approach for every person is a good idea either. Finding some number of manageable types and creating programs for each (which is what we do today) is probably still the best framework. Finding ways to scale the number of manageable types is very important.

Our collective intelligence has developed over hundreds of years and cannot efficiently progress by just letting children explore. We've been exploring for hundreds of years and we must build on what others have discovered, defined, and proven. Little Johnny won't figure out the math to explain why his swing swings by swinging on a swing.

Exploration is incredibly important, but don't discount the languages, systems, and sciences needed to effectively explore, and what's necessary to effectively teach them to as many people as possible. As with almost everything, there is a balance here.