because ricers dont care.
hid kit usually sucks compared to actual projector retrofit utilizing proper D2S bulbs, but i will admit i have seen a *few* "kits" that don't look horrible. but only works on certain cars.
all factory HID are 4300K which is the whitest light possible in the spectrum. anything between 4000-6000K is optimal, 3000K works well too but its just not good looking on the street.
anything over 6K just gets worse and worse. sadly the majority of HID kits are 8000 - 12000 Kelvin, look like absolute ass, and is equivalent to buying an overpriced APC bulb with a fancy "ballast".
All i'll ever buy is a superbright white kit if anything.
I'll wait till i get the Z32 and then get some sort of projector-type conversion kit in there or something... I love having bright headlights -- NOT to blind people (always spend a lot of time lowering and adjusting my lights so it never gets in people's eyes)