I think the issue here is 2-fold.
- Lack of Context: Shermer has no context for Graham's work, and doesn't take him seriously until very late in the dialogue. This is why he just blindly argues, even when he doesn't know what he's talking about. He seemed to develop a sense of respect by the end of the show, but having no context coming in allows him to just label and dismiss Graham and Randall as more "ancient aliens" quacks. Furthermore, Graham's use of the word "advanced" when referring to this lost civilization is difficult to understand for a person who hasn't read his other work.
- Lack of Basic Understanding: Shermer compares the effort involved in painting Chauvet Cave with the construction of the Great Pyramid. To me, this immediately makes debating him on this issue the equivalent of Richard Dawkins debating a Creationist. If you believe something so far out from reality and so devoid of relevant understanding, it's going to be virtually impossible to have a productive debate.
The difference in the two views is extremely difficult to articulate without a lot of context, but here's thing bottom line as I see it.
- Graham likely believes this lost civilization had technology and understanding of the universe, energy, spirituality, and consciousness, that was lost with their destruction (or shortly after) - meaning that WE don't know what they knew! This is abundantly evident by ancient writings from cultures around the world, as well as surviving stone monuments, with their astronomical alignments, advanced and mysterious construction techniques, and mathematically-coded site-layouts.
- Shermer seems to feel that there is an acceptable and gradual developmental incline in human civilization from Chauvet Cave to the Great Pyramid, with Gobekli Type being well inline with this evolutionary path. He would probably laugh at the idea that these lost people had access to knowledge or technology we don't today, as he has not explored Graham's other work on the subject.
In my view, this is a simple issue:
Prove Comet Impact > Validate Ancient Myths > Confirm Existence of Lost Civilization of Seafaring Wisemen
Once the Comet Impact Hypothesis is proven in the next 5 years or so, ancient flood myths from around the world will be (at least in part) validated. Once you accept the validity of these myths (even in part), you must acknowledge the near-certainty that certain common threads in the various myths must be rooted in reality. Since the most common thread between all these myths is the story of Mystics or Wise Men sailing around the world in ships, enlightening and educating more primitive peoples, the claims made for this must be recognized as probable.
Basic inductive reasoning here, but I see no problem with the logic. It seems at this point, the mainstream view is hanging by a thread - and one major breakthrough for the Comet theorists is all it will take to cut it down. What an exciting time we live in.
Now, why does it matter?
If Graham's camp is right, this means a great deal to us. It means that this lost civilization was probably living a far healthier, happier, more scientific and spiritual way of life than our own. They didn't need plastic or cell phones. They reportedly had glass that could bend and could move megaton blocks using levitation (something science can now do on very small scales). They may have even mastered alchemical transfiguration of certain stone types, explaining the mysterious architecture of Puma Punku and other sites.
In short, if such a civilization existed, we should all be interested and dedicated to exploring its mysteries and the lessons they hold for our society. Not only could our own society potentially change for the better in ways we can't imagine, but we may also find that there are dangers the ancients knew of that we don't. Like the one that wiped them out.
I'm with Graham in the belief that the evidence is clear. They were here, they held secrets we can't imagine, and they tried to pass down at least some of those secrets in myth, monuments, and maps. And I think that within their coded messages may lie warnings for future generations - look to the sky, disaster comes from above.
----- That all being said, watching this podcast is like watching an intense MMA fight. I had goosebumps for the better part of 3 hours.