Why isn't Cashmere Thread craftable in bulk?

Most thread recipes follow a pretty simple pattern: two base material and a lightning crystal to make one thread, or six base material, a spindle, and a lightning crystal to make three thread.

Cashmere thread though, it's got that two base material and one lightning crystal pattern, but it doesn't have the spindle variant. It can only be crafted one spool at a time.

Now, when Cashmere Wool was only available as a drop from Vrtra, that made sense I suppose - it's going to be so uncommon there's never any reason to use six at once. Now, though, it's available in unlimited quantities from an NPC. Players can get all the wool they could ever ask for, to make as much thread as they desire in one sitting.

Given Cashmere Wool has gone from "rare extravagance" to "a little bit expensive", there doesn't seem to be much reason not to give Cashmere Thread a spindle variant recipe for those clothcrafters who have made the choice to spend their hard-earned guild points on a key item specifically to avoid crafting thread one spool at a time.