2. Joy and sheer inspiration; why go to the moon, run a marathon, or compose a symphony? Joy and inspiration.
3. Potential to improve our own technology as we strive for the above points. Clear, clear evidence of this in parent's comment and after NASA's innovative tech.
It's irrelevant if you personally don't care, you don't have to do it. It seems there will be billions of dollars and thousands of willing individuals, you can sit back and relax while the rest of us explore the stars.