Gold farming racism

I caught myself using the term "Chinese gold farmer", but after some very derogatory anti-Chinese remarks I heard in WoW chat, I realized that this is a bit racist. The assumption that all gold farmers are Chinese, or all Chinese are gold farmers, is pretty ridiculous. Even my favorite webcomic, PVPOnline from Scott Kurtz, is making fun about it.The only excuse that I can offer is that I once did a WHOIS lookup on www.IGE.com, and the company is in fact registered in Hong Kong. But that doesn't tell us who the employees of IGE are or where they live. And IGE, while being the largest gold farming company, is far from being the only one.

Why do we assume that somebody who is farming gold for selling has to be Chinese? There are quite a lot of third world countries like Mexico, Malaysia, or the Phillipines where you could base a gold farming operation in. You just need people willing to sit for hours on a computer for low wages and having a bare minimum of English. Come to think of it, that description might even fit an US American high-school kid. :) So what has gold farming to do with China?