What's Wrong with Calling them Proto-comics?

Or precursors? Or sequential art? Critic Domingos Isabelinho discusses Medieval painting and book illustration, the wordless engraving cycle, Modern and Post-Modern painting and Concrete and Visual Poetry as entities that can help "expand comics as an art form," then critiques each one for how it is or is not comics. Something doesn't have to be the thing itself to have the traits of the thing; nor do we need to worry so much on giving something from the 15th century a 19th or 21st century label. No, there weren't comic books in the Middle Ages, but there was sequential art and visual narrative. Acknowledging the precursors to something seems to inherently suggest that there are going to evolutions an devolutions throughout the ages, but at least Isabelinho is attempting an interesting vivisection of the intersections of myriad art forms with multiple similarities.