It’s hard to spend money on a nice shirt that is mostly hidden under a jacket all day. Fancy shirts try to distinguish themselves in all sorts of ways (mother-of-pearl buttons, stitches per inch, expensive cloth, and hand cut button holes to name a few) many of which don’t really matter when it comes to the job of a shirt--namely to cover your body and hold a tie. If you’re not wearing a tie, then the collar should frame your face. A limp collar makes your shirt look cheap, or that you bought the wrong size, while an overly stiff collar can make you look very rigid and, more importantly, feel uncomfortable. Primarily on buttondown collars the roll of the point has become an indicator of thoughtful construction. It has an air of elegance in the most simple of things and belies the quality of an everyday garment.
One note: this collar roll is only for shirts with a button down collar.
Collar roll is largely personal preference. It adds a bit of elegance to an otherwise normal shirting element and part of the attraction is the way in which it plans room for the tie knot. Otherwise the tie is pushing the shirt out of the way, which is ironic only because collars are supposed to be made for ties.