Because it is significantly cheaper, designed for the G35 wheel (which is a similar size), and while the Works Bell kit looks good, I don't have any other carbon in my interior - I think it would look out of place.
I'd like to look into a group buy sort of thing, but I'm hoping that we could make this happen for about $300 a pop. I just don't know how the wiring would work since it is for the later model G35 which I believe has a different transmission.