This looks like the makings of a high quality spec from 2004. Granted, CSS should natively support responsive columns, but it's a solved problem. Does he really think that Figure support is what limits web from competing with native? The problem with presentation of web apps has always been that we use a language designed for describing newspaper layouts to structure a dynamic, morphing interface. And its creator wants more succinct descriptors for recreating the above-the-fold of the New York times at variable widths.
It's almost saddening when the creator of something is no longer the guy driving it forward.