If you gave vBulletin a real demonstration, you would quickly find out that it's templates and skinning systems are just as rich as IPB's. vBulletin is as customizable as IPB is, it just works differently.
Also, eye candy isn't everything, as demonstrated by the "Pro" skin of IPB 2, which cut out all the gradients, multiple colors, etc.
vBulletin is still a very good product and worthy competition for IPB.