He's not exactly wrong but "it's ridiculous" is never a good gauge of what's feasible. Most of what we use on a daily basis is pretty ridiculous if looked at from the right perspective.

And while I don't have time right now for a complete rebuttal to Musk's criticisms I will point out that he's being somewhat of a hypocrite here. He's complaining about photon to electron to photon to electron conversion, but consider what might be his ideal: ground based solar power and electric cars. The only reasonable way to make that work is through photon to electron to battery to electron to battery to electron systems, which are every bit as ridiculous and ineffecient as what he is complaining about.