While I wholeheartedly agree with this statement I want to add a huge caution. Many leathers, especially on the modern lower price range riding are very thin. There are actually many types of leather including suede, nubuck, rough out, top grain, etc.
Surely you don't propose that there is LESS variation among motorcycle textiles than motorcycle leathers? In fact I think the (unintentional?) point of your post is that there's _more_ variation in textiles than leathers.