Why buy gold the color of steel? You wouldn't buy a BMW and then put a Ford body on it, would you?
My girlfriend has worn an 18k Rolex every day for a number of years and it holds up just fine. Stainless steel will still scratch and dull over time. The upside to 18k is that it's a soft enough metal that a jeweler can buff it out and the lustre will return like new. Dents and dings come to it easily however, so don't wear it while you're installing mods in your X5.
As for the comment about Rolex being just about status and not quality, I beg to differ. Rolex, like BMW in its industry, pioneered much of the technology for the modern mechanical watch and raised it to almost an art form. A Rolex movement is a thing of beauty. I have a 40-year-old Rolex in my collection that keeps time just as well as the plastic Casio quartz I wear every day to work.