I think you misunderstand who the average SUV buyer is. Most people never use an SUV to it's potential. That includes the roof racks. They basically replaced minivans.
I agree with you in the general case, but the Model X isn't targeted at the "average" SUV buyer. They need to appeal to younger, more active buyers -- people who are more likely than most SUV owners to hit the bike trails or ski slopes. We'll see, I guess.
