The bigger problems arent being solved because the people (or animals, plants) dont have money to pay back..
SV is solving problems for who can pay.. and that crowd already has too many people with their brains working all day to solve their problems..
The problems that are let unsolved, are the ones from marginalized people.. people smashed and invisible to the society.. the ones called the "loosers"..
Even if not targeting social issues.. the big problems and really cool innovations come from passionate human beings.. and not form short-circuit ideas; or money-traps companies.. this is just noise..
The passionate ideas may find a way to be profitable latter.. but it hardly start that way..
I agree with people that say that its hard to believe that really "disruptive" stuff will come from SV now.. because the culture that created the good things for start its constantly getting killed by the people who lend the money for the projects..
it need a long-term thinking, it needs to take a real risk.. the sort of thing banks and angels dont like to invest.. these are traditionally things that the state has invested in.. and the capital folks only get to the party later, when theres no risk..
So unless SV try to get back to its roots, and achieve that.. it wont be that magical place anymore..