While I can see and understand what you are saying, I think that an aspect you have missed is that the art of both creating and playing trumpets is not a static thing. There are always going to be innovations in design and in approaches to the instrument, both from a playing and teaching perspective. You yourself play Monette instruments and at one point I believe you posted a comment about the amount of time and effort Dave and Co. put into R&D, so apparently innovation is still going on and trumpet design is not static. To add to that, Renold Schilke was probably the first person to put R&D of trumpet design into a true scientific format in his approach to fine tuning and coming to conclusions he felt made the perfect trumpets and mouthpieces. Does Dave approach things in a similar manner that Renold did? I hope so.
I agree that many of the large concepts of building and playing trumpets have been defined, but to cut it off to what you think is a simple, static, "blunt truth" is to shut your eyes to the possibility that there is still room for improvement, even if those improvements are small, and it takes lengthy discussion and expansion on the minutiae before the improvements can be made.
Who knows, maybe someone will come out of one of those discussions with a new idea that will revolutionize some aspect of the world of the trumpet once they have had the chance to flesh it out and give it a go. If it weren't for people like that, everyone would be playing the same brand of trumpet and mouthpiece, and trumpet would still be taught and learned the same way indefinitely.