The why so has been outlined and the reasons against have been methodically adressed.
Some people want it done. It would add more content for those jobs that players would like to access.
The negative arguments as to how it would mechanically break the game have been (vaguely) addressed (i could start putting out damage formula numbers and whatnot if you need proof that these weapons are not even near the top of the 'power' pile, but you have even admitted that they are not OP). The lore and other issues have been discussed without much hooplah.
Every reason (expressed) has been addressed at this point. The only argument left is "it would take up valuable dev time" which is responded to with "Changing a job on an item has got to be about the simplist/fastest thing possible". Obviously neither of us are SE devs, but im sure we can agree it has to be on the easy side of the spectrum. Will it actually take 10 min or 2 hours neither of us can factually state. Only that it is simple relative to other changes to the game.
When something is desired and all reasons not to do it are dispelled, you do it. If you want all jobs on Kclub then id suggest making a simlar thread for it. SE is not some all knowing entity that never falters. Maybe new jobs should be on Kclub. Just because 1 guy didnt get what he wants is NOT justification to deny someone else a toy. Thats just petty and spiteful.
I want a candy bar!
"It costs to much money!" // "Cupon. Its 5C."
"Its bad for your teeth!" // "/pulls out toothbrush for use after"
"No one can take you to the store!" // "Stores across the street. Ill walk."
"Its to many calories!" // "I do 3-a-days for football 5 days a week"
"You havent finished your HW!" // "/hands over finished HW"
"Well...I cant think of a reason you DO need a candy bar. Prove to me you need one!" // "/facepalm. Its because i WANT one and you can provide no reason i shouldnt"
The REASON is desire. Thats it. Some people desire it. They do not need to make you desire it for theirs to exist. If something is desired, can be provided for vitually no cost, and has no negative effects on anyone, and wont piss off a billion people, then there is no other justification required in regards to a videogame update.
You are saying those in favor must prove a need for it otherwise its not worth doing. Its a game. No one needs anything, let alone be able to prove to someone else. The desire is adequate justification in that situation. There must be a strong negative in-game consequence(balance), playerbase backlash, or prohibitive costs. If there are none of those, then desire alone is enough justification. So far, the only hurdle presented is how much dev time it will take because none of us know that answer explicitly. This is where an SE dev would tell us what the dev team think about feasibility.
The "Why so" category once all qualms have been addressed is just defending the status quo for the sake of the status quo.