I would disagree with this only because it makes blacksmith repairs completely useless.
I personally miss the time of having to go and find player blacksmiths in the corner of britain to repair or craft me new armor. That is something the game has lost along the way and won't get back.
I'd feel bad for the smiths if they couldn't even make the 10 gp off of repair contracts anymore because everyone had their own 'fix my stuff' bag.
I think the OP meant a bag for the CRAFTER to use.
That way, for example, a person could unequip their gear into the bag, pass it to the crafter, and the crafter repair the stuff in one pass. Would actually make the old-style repairing for others easier...
As the Salvage Bag requires you to STILL have scissors to salvage cloth/leather, and a smith tool, and be by a Forge & Anvil, to salvage smith items, AND require skill checks (tailor for tailor, mining for smith), a repair bag would STILL require the skills to DO the repair, and the tools as well. And, like with the salvage bag, skill checks are involved to see if you can repair an item, and if there is durability loss.