I never thought of it as anything to do with white kids - it is Japanese cars that are updated in the F&F style. If anything, it is a derogatory term for hot-rodding a non-American car in a cheap and "non-tasteful" manner. (Of course, non-tasteful is a term that is open to interpretation - people do all kinds of things to cars that I would not do to a car of mine, but if they derive happiness from it, who am I to say anything about it).
I really do not think it is really aimed at the owners as it is at the origin of the car. Of course, It is probably the same as referring to cheaply modified American cars as red-neck cars.
FWIW - My old Miata is slightly lowered and has a chin spoiler and a small rear spoiler - and someone once asked me why I riced it. The answer was that it was within the rules of the road-racing class I was running at the time. I do not think that it is tasteless, but I suspect some purists are not fans, and that's ok. I do not think the spoilers do much, but the lowered suspension definitely improved handling on smooth tracks.