If I may paraphrase (bastardize) FDR's famous quote:
I choose to photograph the moon in this decade and photograph the deep sky objects, not because it is easy, but because it is hard.
The challenge is definitely an element of why I enjoy astrophotography; the pay off of overcoming that difficulty is quite rewarding. But the learning curve is no joke...astronomy, photography, computers, physics, and math all come in to play in just the process of setting up the equipment and taking a single picture. Then there's the whole other technical and artistic challenge of post processing the images to make the final product feel authentic in color and intensity, to remove imperfections of the light train, camera, noise, etc. I won't lie, there's a pride (if not a stroke of the ego) to being one of a relatively small community of people capable of such a complex hobby.
Another quote I can relate to is from Edwin Powell Hubble
The history of astronomy is one of receding horizons.
Astronomy, like many sciences, sees as much as it can with what is available and then pushes to see further. It started with our eyes that see just the "visible spectrum" of light and within that only light at about the 6th magnitude of brightness (comparable to a single candle's light in a pitch black environment at about 3.6 miles away), or brighter. Yet we know the full electromagnetic spectrum is wider and that there are plenty of objects dimmer than the 6th magnitude. Through astrophotography we can see more, in perhaps every sense of the word.
The telescopes themselves, just lenses and/or mirrors, can focus dim targets to make them bright and visible even to our naked eye. Their magnification makes what's otherwise tiny and unresolvable, an eye full of detail.
The camera sensors can easily see well above and below the visible spectrum then convert that data into information displayable to our naked eye. Further, they can observe in a way our eyes can't...they can leave their "eyes" open for an extended period of time to aggregate the small number of light photons in order to expose extremely faint targets.
What about all of the beauty here on Earth?
I, as many, see beautiful things worth photographing all the time in my day to day life (if only I had my camera permanently at the ready). Taking nothing away from the amazing vistas, animals, natural wonders etc. that we see so frequently, in a sense they can be pedestrian. Anyone in the same place can witness them to their fullest without effort or enhancement. But, we know there is much more in existence than just what we can see and as with anything in nature, it is often both interesting and beautiful.
In any other arena, like a sport, average doesn't excite. What excites is when the athlete goes beyond, demonstrating that they can run faster or jump farther, etc. To this end, we develop new athletic technology yearly to improve performance in every measure, even if only by a smidgen.
I see astrophotography in a similar way. If there are amazing subjects to photograph daily with average human eyes, how much more amazing can a picture be when taken with tools that extend the reach of our senses a thousand fold, or more! What if you could see beautiful and real objects that were otherwise invisible to your bare eyes?