They have never existed at this sheer volume and this vocal. I never even heard of a merc until I came to Asura.
Oh yes, it is very different. There is a reason SE put rare/ex items into the game....
Mercing as it is done now is also breaking the mechanics of the game. Using multiple accounts, running multiple instances of FFXI and scripting commands on one computer is against the TOS. End of story.
Unless, of course they are sitting around 6 desktops with incredible multitasking skills.