[jasode]

I think you missed the journalist's jaded sarcasm embedded in "No one will ever be invited to explain that in a TED talk."

I'm guessing TED has had 50+ presentations on "solutions" for Africa over the last 5 years. We'd expect that some of the ideas have failed to deliver. However, we can't expect TED organizers to give stage time to followup presentations explaining why they failed (or why the ideas at smaller scope didn't scale up to large one like they hoped.)

So yes, we would get more value out of hard-hitting TED talks explaining warts and difficulties but we can't expect TED themselves to highlight it. A similar concept is "publication bias" against negative or non-repeatable research results:

http://en.wikipedia.org/wiki/Publication_bias#Definition