This is a defense of glass, specifically, and not a class of architecture in general. And "traditional" architecture is not a properly descriptive term; it tells us where the architecture came from, not what it is. Architecture is basically a creative process, and we can't handwave away the complexity by using temporal language like "traditional" and "modern".
The problem with modern architecture, in my opinion, is its preference for "dramatic effect": long contours, flat surfaces, high contrast. This is visually exhausting. It looks nice in a catalog and from a large distance, but it's uncomfortable to be close to. This doesn't follow from the use of more glass. It's a historical coincidence that the float glass process made windows cheaper around the same time that architects started experimenting with smoothness.
The problem with modern architecture, in my opinion, is its preference for "dramatic effect": long contours, flat surfaces, high contrast. This is visually exhausting. It looks nice in a catalog and from a large distance, but it's uncomfortable to be close to. This doesn't follow from the use of more glass. It's a historical coincidence that the float glass process made windows cheaper around the same time that architects started experimenting with smoothness.