I can't tell if you're saying that bicycle design is a 'solved problem' or if everything that can be invented has already been invented. Either one is a perfectly valid excuse for not looking at anything in an entirely different way, I suppose. People thought that fire solved all their energy needs for thousands of years, right?
Though the seat does look a little far off the center of gravity to me.
I think he's saying that the designer should've started off with understanding why the components of the modern bicycle exist in their current form, in order to more effectively find ways to truly improve them.