The 'Everyone-has-the-same-nickname' Syndrome

Ella Malaka.. Vre Malaka... What's with calling people - 'malaka'? It's unavoidable, yet strangely enough I keep hearing it more and more now. The English equivalent of the word is 'wanker' but as you'll notice from the wiki-link that I included, the word could have more than one connotation to it, and depending on its context it could either be a bad form of profanity or a cool way to greet your friend.
I've always wondered why Greek people, by and large, forsake the usage of the person's first name and directly fallback on the widely used and stereotypically accepted nickname - malaka. I guess it's either because they have a really bad memory and feel the need to call everyone by the same name, or they must have this insurgent need that the world owes them something in return and so they exacerbate whomever they meet just so they can make themselves feel better. Whatever the case may be, the intonation of the word has a negative sounding appeal to it. I don't think anyone would welcome such a lewd, debasing label.
One day, on my way back from work, a seemingly polite person stopped to ask me for directions. At the time I was new to the area and my Greek speaking abilities were somewhat lacking. As I started speaking to him with my profound English accent I noticed that the guys face started to distort itself from a mild smile to a strikingly deformed grimace. I presumed that I must have had something on my hair or I must have forgotten to comb it that day. But contrary to my presumption, he started to scoff me and say, "ante vre Amerikanaki...den ehw oli mera;" and that's when I heard it directed at me for the first time. He waved his hand off at me in an aggressive manner and blurted "ante vre Malaka..." and then took off mumbling a slur of words out loud that -at the time- I couldn't put two and two together. He suddenly turned from being a somewhat pleasant fellow to a beast in less than a minute.

God Forbid: God forbid you should ever get yourself mixed up in the 'malaka-loop.' This happens when both parties end-up exchanging the term until the victor comes out gratified in having said it more times and with more gusto/pazazz. There is no object to the game; only the fact that both start ridiculing themselves with 'malaka-gestures' until their mouth gets tongue-tied through wear and tear of the word. It's actually a scene to behold...