Why Is Buying Gold / Gil So Bad?
First and foremost, gold farming just wrecks plain havoc upon the economy of the game.
Unlike IRL (in real life), all users start on a level playing field. That's good because there should be no advantage to you in the game if you're rich in real life.
Once you bring in gold selling/buying, then people can get unfair unadvantages, and spoil the way the game was supposed to be played and enjoyed.
This may be too idealistic, but I, for one, play games simply to get away from things like this.
Over-value of Powerful Game Items
Gold buying/selling also causes items that are being auctioned to become over-valued, because players can purchase large amounts of gold to bid for the items.
This puts the purchase of powerful items out of the reach of the player who doesn't purchase gold using real money. Very unfair!
It takes a lot of skill to use a high-level character's abilities to their fullest, so an inexperienced player that has purchased a high-level character will very often lose a battle or die because they don't have the experience of all that playing-time.
For me, the point of playing these games is not to win -- it's to be immersed in the worlds, and to interact with fellow players. You miss out on truly experiencing the world if you don't earn your items and character abilities.
