California bleeds money into unpaid medical services, for a variety of reasons that includes illegals. I would also bet that there are a lot of younger age group Californians who don't have insurance because they don't either don't work traditional jobs, and/or they just don't want to buy it. For all the UC system hospitals the state picks up the tab for the money they bleed.
They probably think Obamacare will fix this by making people buy insurance, but it won't (in addition to being unconstitutional).