Do you have any evidence that it isn't true? :) A wealthy family, if you have one, would be an excellent source of money for a startup.
It's sometimes hard to tell which bits are for real, and which bits are the play-acting, but I've long suspected anyway that more people than you'd think are playing startup. Does it matter if it's with somebody else's money rather than their own? I say no... but of course if your story fits the rags-to-riches American Dream then this can help ennoble what would otherwise be a straightforward tale of simple money-grabbing.