I know i'm a bit slow to post, and many people have probably already said this but anywho.
I'm currently doing marketing, and we've recently started talking about how damaging it could be targeting a "lower" market for a prestige product (e.g Ferarri making a budget car - would lower the prestige associated with the brand)
Same concept with the GTR. The GTR is clasified as a super car. It has been released as a Supercar, all that the R35 stands for is the GTR.
Whereas the other skylines so far have obviously had the GTSt/GT-T's AND the GTR, but the GTR's weren't marketed this much, and weren't as sophisticated as this thing.
I probably just spoke a whole lot of crap, and it probably doesn't make sense