He has baggage - his father, being the most immediate example of that fact. I really admire the man - moreso than Ron Paul, in fact - but I think he's better off doing something purely economic. From an 'executive' standpoint, Schiff has a lot more experience that will trump RP's, and I think a lot of people, considering RP's age, will ask themselves whether or not they would want to see a President Schiff... and I don't think a lot of mainstream voters will answer yes to that question.
Better to go with somebody more mainstream and viable and then *hope and pray* that Dr. Paul doesn't die whilst in office - IMO.