Note that this is a concept, take any terms as abstraction, i.e. "item quality" can mean anything, from selling value to merely the name of the item.
Why do people like combat, but not crafting?
How does combat work?
Combat forces you to make decisions and game/genre experience determines the result. If you do stupid things, like casting "Cure Wounds" on an uninjured party member, you will end up in trouble. Combat is inherently limited - by hit points. Your goal is to get past the enemies without losing your hit points. The quality of the battle is determined by the amount of resources you spent - hit points, spells, potions, etc. and the difficulty of the encounter. If you didn't spend or lose anything at all to win the hardest encounter, it was the best possible fight.
How does crafting work?
The goal in crafting is to have a usable item, with the best item quality and the least consumed amount of resources. You can't call yourself Grandmaster Tinkerer before you can craft a crossbow from a paper-clip and a goat.
You see the similarities, right? But if both tasks are very similar - we just need to combine the fun of combat and the process of crafting.
When crafting an item, the player has a limited amount of whatever. When this reaches zero, there will be no item (battle lost). The player has to choose an option. This decision process must/can be reevaluated periodically. The core options are "finish item" and "improve quality". Now, this is still no fun, because when you say:"You can choose 10 times.", player picks 9 times "improve quality" and the last action will be "finish item". Like combat grants you more options than "hit" and "run", the options need to be expanded and the results slightly randomized. More skill level would allow more options.
When the enemy poisons your character, you either cast "Cure Poison", drink a potion or you try to finish the opponent faster.
So, you can add random events to the crafting, like "Sneeze attack". If you are experienced or have the right item (handkerchief), you have an option to solve this problem (it still costs you an amount of whatever). You can also decide to live with the event - it might lower your item quality or your amount of whatever each turn, but maybe this is still better than investing the costs for the cure or the event might even do something good (adds option to disease opponents). If you do something stupid, like solve the Sneeze attack with black powder instead, you will face consequences.
I guess what this concept is basically about is: Crafting should require decisions (beyond what to craft) and have consequences, to be fun.
