I listened to the podcast as well. Tom Rosenbauer is certainly an institution as an author and fly fishing advocate. I was a little nonplussed by his approach, though. It wasn't clear to me whether Tom was serving Cameron open-ended questions to elicit basic info or whether he was being truly negative about glass.
I'm guessing that it's a bit of both. For additional context, here's an interesting article written by Tom that ostensibly describes his love affair with Bamboo. He starts out, however, with some background that includes building his own Orvis Fullflex rod from a blank in the 1970's after starting with other rods including a Wonderrod. He also describes fishing with Orvis SFG rods starting in 2018 or so. So he's not a total stranger to fiberglass the way almost anyone who started fishing after, say, 1985 might be.
Worth a read.
https://www.chrisclemes.com/post/classic-story-what-makes-bamboo-so-special-by-tom-rosenbauer