If SMN burning is not cheating, in what universe can you claim with a straight face that Abyssea Leeching is?

Keep in mind, the rules of the game are not yours to arbitrarily implement. To cheat at the game is to do something that is against the rules of the game. When no rules of the game are being broken, the use of a mechanic is not cheating.

The rules of the game are set by the Developers and Staff, not by history, tradition, or the player base. They have stated numerous times that Smn burning is not cheating, and have made no statement either way about Abyssea Leeching despite knowing of its existence. Until/Unless it is adjusted by them, or they comment on it, one can only assume that it does not break any rules.

Finally, you and Akujima tend to use a particular backwards argument when dealing with this sort of thing that just drives me crazy. "FFXI is an RPG and thus X, Y, and Z need to be in it". That's not how it works. You are trying to define the game based on its genre when it is the games themselves which define their genre. You do not look at FFXI and say "Well this needs to be an RPG, so the game needs to be this". You look at FFXI and say "Well, in this game you control a single avatar who explores the game world and gains experience points and skills, gaining new abilities over time, so you could call this game an RPG."

FFXI is FFXI. If it changes enough that it "does not deserve the title of RPG any more", they can simply change the genre. Not that your video game purism isn't wholly unappreciated nonetheless.

Also, there is no accomplishment for leveling jobs and never was. People really need to get that through their heads. I've seen level 30 players who were better at their jobs than "Main Job", old-leveled 90s who were too dense to look up even a single shred of credible information in their 7 years of playing the game.