It's an easy question to answer. Science is economically and culturally important.
As Phil Plait discusses on Bad Astronomy, Stephen Moore of the Wall Street Journal says that we shouldn't fund basic research because it is innovation in industry that brings the economic returns. That is nonsense. Industry innovation would come to a shuddering halt without basic research. It's curiosity-driven research that provides the fuel that industry uses to produce new products.
Funding science provides more than a return on investment. It's also about understanding the natural world. The Universe is a fascinating place and we humans (with exceptions like Stephen Moore) are deeply interested in finding out about it. To me, the accumulation of knowledge should be viewed as the primary goal of science. Commercialisation of that knowledge is just a welcome side effect.