Question: why is seeing and capturing the X a big deal?
For 99.9999% of humanity, it is not a big deal at all. There is really no science to be done here, after all the Lunar Reconnaissance Orbiter has fully mapped the moon down to the meter resolution level. The "X" has been know about for at least a generation, so it is not like I am the first to see it. And the reality is that outside of a few nerds here and there, nobody cares.
But I do. The "X" is only visible for about an hour every Lunar month, and it is only visible to the US in dark skies about 2-3 times a year. So it is a rare thing to see. I've seen images of it, seen video of it, seen other people excited about the "X" but never got to see it with my own eyes before. Seeing something is an entirely different thing and looking at a picture. Take for instance, oh, at random.. The Antenna galaxies. I can show you amazing photos from Hubble and some of the big telescopes in vivid colours swirling texture and amazing detail. I've seen them with my own eyes and they look more like this under very dark skies and clean air with no moon out to mess with your night vision. Honestly, seeing them takes a 12" or larger telescope, a few hours to get acclimated to the dark, make sure equipment is in tune etc, and is a pain in the rear. Most people are never going to go through that effort to see something that a normal person will say "that it?"
But there is something more than just looking. It is the knowing that a few measly photons of light traveled at least 50 million years uninterrupted through the dead, dark of space and ended up triggering a chemical reaction in the rods and cones of the eye of a hairless chimp on a tiny spinning ball of iron covered in silicate rocks. An event that otherwise has no purpose in the grand scheme of the universe impacted the eyeball of a creature with enough brain and mental energy to say "I understand."
When I give telescope classes, I get sort of laughed at when I talk about the, and I hate this word but it fits, 'spiritual' aspects of astronomy. Looking at the sky, seeing things that even 100 years ago were not understood, not known, though impossible and you get a sense of scale and awe that is hard for me to put into words. I've seen, with my eyes, a galaxy whose light has been traveling longer than complex life has existed on earth. I've seen with my own eyes the proof that space-time curves, that gravity bends light, and at the same time had light that traveled roughly EIGHT BILLION YEARS hit the back of my retina (This took a special night at a star party with a 30" telescope. The owner screamed at people to come and look; he had a line all night and the guy was in tears he was so happy he could show people something that defines awesome in every sense of the word.)
So, why is the "X" important? It is something that I have wanted to see but either get clouds, or work, or I forget to set an alarm, all the little ways that I have missed this over the years. For the same reason that tonight I am going to freeze my ass off in windy freezing frost-laden air to get a picture of Jupiter with two moons, two shadows and the Great Red Spot all facing the earth. I'm so expecting to suffer to see this that I preemptively took tomorrow off to recover. I've seen this image with the Hubble and from people far more advanced in photography than I but I have never seen it with my own eyes. This comes back to why I do outreach as well. When someone at random comes across you and your gear in a park, and see the moon for the first time, or Jupiter, Saturn's rings, and exclaim "you can see that!??!??!" or "I never knew you could do this" I see the same thing. The seeing... that is something that you just cannot duplicate in any other way to make it have a meaning.
The 'why' is a great question. Thank you for asking it.