Consider, if Columbus had been funded by some Renaissance version of NASA, we'd still all be over in an overcrowded Europe, while waiting for the latest "test" ship to return from having set a foot on the New World and come running back.
Further, if you think that the only thing we get from robotic missions is "pretty pictures" then you are sadly mistaken. In fact, robotic missions will be highly instrumental to making human spaceflight possible, such as measuring the radiation fields that exist beyond the safety of the Van Allen belts, and testing out various methods for dealing with that radiation, in particular cosmic radiation, which is mostly composed of very high speed protons (i.e., cannonballs moving at near the speed of light, basically). Thus, even for human spaceflight, robotic missions are indispensable.
