I've seen a bunch of HN comments over time claiming that Tesla has no battery technology, because they don't build the basic cell. Turns out that battery packs are more than just the cells they're built out of.
At utility scale I expect it is a very simple design problem in fact. It's harder to design them for confined spaces or for crashworthiness but for a fixed installation with no geometric constraints it would be a piece of cake. Anyway Panasonic already has this expertise since they deal in utility projects elsewhere (and in America according to the other comment).
Because the world we live in has certain types of people -- politicians, lawyers, business executives -- that don't solve problems for the world as in, "what is the most efficient way to accomplish this;" rather, they solve problems as in, "what is the most efficient way I can enrich myself.
I guess it's maybe rational in a self-interested way--no longer do we live in a world of many competing tribes advancing ourselves for our own survival among competition for scarce resources. We live in an increasingly globalized world with a class structure and an overabundance of resources. Or, in other words, "the scarcity problem," as Keynes put it, has pretty much already been solved--at least in terms of survival we have enough resources to feed, cloth, provide shelter and basic healthcare to every person on the planet, but we don't. The answers to that are some of the same reasons.
In a general sense is it not better for all people to be in he business of creating value than to quarrel over transferring it from one to another? I believe that if you care about human welfare, then it is obvious that it is.
Because distribution of value is important, and people believe that distribution of value is important. After all, there are limits to how much I can feel your well-being, and vice versa.
I actually support wealth redistribution, and I even buy in to the concept of diminishing returns in utility to increases in wealth, like you said--though, economists do debate whether that's actually true.
