Wouldn't you expect a bunch of criminal sociopaths that shoot people in the face for cash to call each other something rude?
I suppose, I just find it mildly annoying hearing it in places it shouldn't be used. Its odd and jarring to me, which is why I dislike it. But I merely started this thread to find others opinions of the word, so its nice to hear them 
Well, think about the word "Nigger" and the difference between what it means in Dublin and Harlem (And what Irishmen should be careful saying such things in Harlem!).

Things change depending on the local and cultural impetus.
Also, I've seen it mostly used in Seattle. Most likely it's a Japanese Loanword used in Seattle's streetspeak that was gotten because the Salary-men from the Japana-Corps kept calling people on the street that, which, would you say, is the proper usage of the word? (After all, you're not about to be polite to a street punk, right?).
Finally, well, rule of cool. Omae is easy for Gaijin to say, and sounds like something that would creep into the jargon, savvy, my droogs?