Absolutely right. That kind of finite-element simulation is futile because it simply "enacts" stuff that we know about. Sure, it might behave in ways we didn't foresee when we scale it up a billionfold, but it won't show us anything genuinely new. I suspect there is stuff going on in neurons that we don't even know how to look for. Well actually I *know* there is, because neurons are conscious.
Aside from these philosophical objections, Markram's model doesn't even include glia, which are fully half of the interactional dynamics going on in the brain. We scarcely even know what glia are doing, and yet they are part of every synapse and their slow waves of activity strongly shape neuronal processing.