I my usability work, I have often come across clients and employers who confuse my field with that of graphic design. To be clear, graphic designers are primarily artistic and can produce some of the most breathtaking websites around.
There is one artist whose work as a graphic designer I particularly admire and I sometimes go there for inspiration. The main problem is that the websites are all in Flash which can be slow to load, impossible to resize, and whose contents are not indexed by search engines. These are not absolutely fatal issues, but they don't help.
Usability on the other hand is quite focused. It can be measured objectively against stringent criteria and is closely related to psychology (the first investigators into human-computer interaction were mostly cognitive psychologists though it has since become more multi-disciplinary). But should usability people ignore aesthetics?
Some say that they should Jef Raskin felt that usability was the primary key to any human to computer interaction: without it, such interaction would always be a failure. Aesthetics came second to usability concerns. Others like the clients and customers I have mentioned above feel that usability is just a branch of graphic design. Indeed, I turned up to a firm in Texas for 2 weeks of work once. They said they wanted a usability expert but really wanted someone with an artistic eye. This was a failure in requirements gathering that I have since not repeated.
But most design these days occurs within a team. It is very rare that a single person undertakes to design an entire product. Within the ideal team, there should be experts on all aspects: designers, programmers, and usability experts to fly the standard for the users who can sometimes be forgotten in the rush to produce excellent work. However, all members of the ideal team should know something about the demands of the other team member's field. For myself, I have an appreciatin of art though I do not claim to be a graphic designer. I like taking photographs and some of them are not too bad, though I am not Henri Cartier-Bresson (and his Magnum Photos.
Likewise, I am no Donald Knuth, but I know a little bit about programming and have produced my own program (for example, SalStat, indeed enough to know what things are and are not possible when building a product. When producing work, I know when something is demanding the impossible.
At user:number 1, I often find that the aesthetics are extremely important in a customers mind and I have to pay attention to them. This is no problem because in my view and experience, they can be easily fitted together with a usable interface that is programmatically possible. All this means that customers can have the product they desire. Indeed, I often find that in programming terms, a more usable interface is curiously easier to program and design around. Indeed, I have contacts within the design world that I can bring to a design specification so that their work along with ours produces interfaces that are not just wonderful to look at, but are also simple to use.