Shrink wrap is one thing but custom software another. You cannot expect software developers to be graphic designers. We rarely understand the use of good white space, font size, color schemas, and all of the stuff that goes into a good UI experience. But customers don't want to pay for that. So the stakeholders and their entourage of project managers come back to the dev team mid-way and say "gee how come it doesn't look cool like web site X?"