So what to do with a billion Euros? Obviously, we shouldn't put everything in a single pot. Particularly not in one crazy pot. That's why people complain about Markram's ego trip and enabling politicians. If you got a certain amount of funding, diversify: fund a couple of cranks, sure, but 90% should go toward what's often called normal science where small steps add up to comparatively predictable progress.
(In Markram's/the HBP's defence: Ultimately, the project will yield a metric tonne of normal science, especially in terms of infrastructure etc. However, everybody will be disappointed at the end...)