Some people like to level alts, and they often prefer doing it fast; aka powerleveling. That includes me! If I didn't know how to create potions and I'm leveling an alt, I would empty the auction house of suitable potions, flasks and elixirs because they make leveling easier, being filthy rich I often ignore the price tag too.
There is just one downside usually... there are none for sale!
This is where you can step in. There are certain potions that are very useful for leveling and there should always be some for sale. Usually people don't create lower level pots/flasks/elixirs because they can, but only because they are leveling the profession. That's not nearly enough!
It's true that usually herb prices are too high to make profit from alchemy creations, but this is not always the case.