IMHO you are missing nothing. A lot of people I know fish for tarpon with a straight 80-100lb in cuba, etcRather than butt, "class tippet" and shock/bite tippet sections, with fancy connecting knots, why not use a simple, straight piece of 80lb. flourocarbon? Fewer knots to fail. If the fish are not spooked by 80-100lb. shock tippet to the fly, why would a longer piece be a problem? Only two reasons come to mind: 1) you're hoping to set a record with a "class" tippet, or 2) you want a tippet you could possibly break if necessary. Am I missing something?