Many young web designers view their craft the way I used to view pop culture. It's cool or it's crap. They mistake Style for Design, when the two things are not the same at all. Design communicates on every level. It tells you where you are, cues you to what you can do, and facilitates the doing. Style is tautological; it communicates stylishness. In visual terms, style is an aspect of design; in commercial terms, style can communicate brand attributes.

It can also convey the designer's contempt for the subject matter. "This is boring, so here are some stripes and here's a drop-down menu, so you'll know I'm better than this stupid assignment." On this level, style is an underground language, from one peer to another, having nothing to do with the site's visitors or purpose. Indeed, this stylistic appliqué can interfere with the site's purpose. Then the usability gurus step in, blaming Design for the failings of stylistic fetishism.

Style vs. Design - Why understanding the difference is what it's all about
par, et via Jeffrey Zeldman