This might seem like a very niche topic, but I think it has an overall, quite significant effect on the profession economy.
Leather and cloth are a LOT easier to obtain than the other crafting reagents, which, in a normal economy would mean that the other reagents price adjust to the amount of effort put into obtaining them and become much more expensive.
The existence of Leather and Cloth Transmutations upsets this balance as if the price of the other reagents rises too high relateive to leather and cloth, it creates an arbitrage opportunity for transmuters.
While WOW is far from an efficient market, this arbitrage will eventually cause the price of the other materials to settle on roughly double that of leather and cloth.
Blizzard really should calculate how much more leather/cloth is being obtained “raw” than the other materials and adjust the transmute accordingly, removing the arbitrage opportunity and allowing the price of other reagents to rise to their true level based on the amount of effort needed to collect them.
In the current system, people who just want to be herbalists or miners are at a huge economic disadvantage as there is no possible way currently to collect Ore or Herbs faster than being a skinner and then transmuting your results.