It would be cool if crafters could "engrave" their stuff with a logo or initial. No in-game benefit to the item but a fun little extra that would add a bit of depth to the crafting world.
Extra 100 item power if you crafted the item by yourself. Nothing feels like stuff you made by yourself. This would promote crafting for other reason and something else than just making cash.
There is already an oversaturation of the market. Any optional system's that force people to use them, are bad design.
Even PvP is 100% optional in this game. As a player, you never have to leave the safety of the blue zones. That's not to say they can experience everything the game has to offer,
but the game doesn't force you to PvP. Your proposed change would force people to craft for a very tangible bonus regardless of what other content they are doing.