This is not really new to MMORPG's to be honest.
I agree and dont agree.
Gold farmers can be a real pain. Not cause of the english but the fact they only there for the gold. Often you hear horror stories of them Ninja looting pieces when leaders of loot etc. I have seen this often on UBRS and Scholo Raids.
A good example of this is Lineage 2.
Since lineage 2 has open PvP, farmers use this as a way to exploit items from innocent players. Often by hitting you with a hard bleed then pulling monsters on you...(so the monsters take final blow on killing you and not the Farmer taking murder penalty) He then loots your items...sells them and hands cash in. This is a rare example but one i have seen performed.
I often used to torment the farmers on WoW. When they hunt Elementals i used to banish them with my warlock
Interesting fact though....bit different but...
On Lineage 2 i managed to speak to a farmer who spoke English really well. She went into how it is an industry now. She was in an office with 40 other people playing Lineage 2/WoW/Eq 2 etc all farming gold. They had to make a certain amount within 12 hour session. Of course all shift work too, changing people all the time. So it is a 24/7 service.
She clearly said they dont play it like it was a game...but as a job. They dont really care for other players and also admitted they
DO ninja but in her term "Borrow" Loot from raids for cash.
Once they get the gold for the day they all mail it or hand it to a level 1 mule.
They then advertise on Ebay or Gold buying websites such as ige.com and sell the gold for real money.
Hence where term Chinese Gold farmer comes from. Since 90 % of Farmer market are chinese business selling gold online in USD. Making a killing of cash.
So you can see where grudge starts against these people.
Ncsoft...Of lineage 2 banned a whole load of farmers last year...resulting in 1500 accounts +- a server. That is a good example to show how many and how big business is..That is just per a server!
I think blizzard needs to start cracking down on Farmers + Gold being sold online to resolve this.