This was posted on one of the videos on the channel of archaeologist Flint Dibble (yes that is his real name, his dad is also an archaeologist and his brother's name is Chip).
As it said, he debated Graham Hancock on Rogan because he felt Rogan's audience needed to hear from an actual archaeologist about the nonsense Graham Hancock was pushing and hopefully get them interested in real archaeology, which I feel is a solid reason for going on Rogan and doing what he did. Too bad more actual experts aren't asked to go on Rogan.
Plenty of people ride dinosaurs!