As a constant pugger, I find acomplishing certain ahievements to be near impossible, if not downright completely impossible.
Usually the fault is not my own. I won't entirely pass blame- I have occasionally stood in fire a smidgen too long in an attempt to get off one more heal. But normally achievements are just out of reach due to one or more individuals in the pugs that I've joined.
Pugs are constantly unable to muster up the coordination required to accomplish many of the achievements available. At times, they're too uncoordinated to even kill simple bosses.
And so, with many simple achievements and their rewards unatainable for puggers like myself, I read through "achievement X for sale for X amount of gold" advertisements with a little longing.
Trust me, I wouldn't want to simpy afk out during fights and have my achievments handed to me. But at times, after constanty running with fail pugs, I would love to join a group that has mastered all fights, allowing me to participate and to feel as though I accomplished something during the run.
However some people do purchase achievements with the primary purpose of setting autofollow and leaving the computer, expecting to come back and have ther character suddenly be elite. Those people then hit the general population with outstanding gear but still lacking the ability to play the game.
People like that set a low precident for those of us who simply want to experience fights at the level of high end raiding guilds.