I think the missing info here is that Musk gave the non-profit the initial $100 million dollars, which they used to develop the technology purportedly for the benefit of the public, and then turned around and added a for-profit subsidiary where all the work is happening.
>>jlmort+(OP)
He has plenty of standing, but the "supposed to benefit all mankind" argument isn't it. If that were enough, everyone not holding stock in MSFT would have standing, and they don't.