Imagine two startup ideas. One, could be profitable, and eventually turn into a $100million company that does something useful. The other, will never be profitable, but makes promises of being worth $40billion. Which one gets the (inexperienced VC) money? The second. Which one would be a long-term bonus for the U.S. economy? The first.
That is the problem; too much money from Softbank (much of that from S.A.) pushes all the developer and other resources into goofy ideas that will end up going bust, instead of more rational ideas that could be long-term useful.