>>71. It is several times cheaper than the Shuttle or rusty Russian rockets.
2. It is safer.
3. The engine is reusable.
4. Made completely by a non-government company.
5. A lot of new technology put to use on every level.
6. First step towards moon excavation and terraforming other planets. Since to do that, you need to launch a lot of stuff into space at a cheap price.
You can't perform large scale terraforming experiments on Earth. I.e. the ones which can be done using self replicating robots. People are afraid of even terraforming Earth deserts, since results could be unpredictable. So other planets like Mars are a lucrative resources.