Traveling to space isn't the same as canyon rafting or bungee jumping. It's not just "exciting", it elicits a wide range of profound experiences and deep emotions. And all of them are just as valid and should be affirmed. If you are organizing and leading people into space, you have to be fully aware as well as humble.
Over the past decades, Bezos spend mountains of energy expounding the importance of space travel, including its philosophical aspects. Bezos response to Shatner makes all of that questionable. It leaves one speculating whether or not he sees commercial space travel as anything else then another thrill ride that might add to the profit margins of his companies.
Maybe he did have a deeper discussion in private. But given Bezos' public image and demeanour, I wouldn't assume he fully understood the importance of that moment before the camera's in hindsight.