surely, the official answer will certainly for the USER, the CUSTOMER, off cause.
but is it true? is it really what designer thinking? let's us look at a example:

this is the last generation of bmw 7, that is the most exclusive car under bmw brand. it is elegant, luxus and high-end. so the real target buyer are, those who can afford such a car, a high-range manager, business man,, maybe 50 or 60 years old.
but if we look at the old one, we can notice that, this car expresses a very progressive image, exeptional headlamps , a remarkable back, that we never saw before. bmw broke rules and set up new milestones for a car.
I have to admit that, this is a really powerful and iconic design. A very big step of bmw. however, as I just mentioned, "who are we deisning for?". the bmw designer did a exellent design, but forgot the real customers. this fact was also shown by the sell numbers. this bmw 7 is not as popular as it should be. it has been beat hard by Mercedes s class. (see pic below)
a real successful design, high classic, noble and luxus, though it expresses a more conservative image. this s class was addressed on the exact right position on the market. 2 weeks ago, the newest bmw 7 has come out. we can clearly see that, the design goes a step back and shows a more mature, cleaner design. maybe, some designers will say, there is nothing new on this car, but don't forget and ask yourself "Whom ar you designing for?"the new bmw 7