For me the biggest advantage is that they do backend stuff as well, which since that is God's most tedious job, is a real bonus. It is so much easier when you have somewhere to start.
Best advice I've ever heard on design is "copy, copy, copy, copy until you don't need to". Themeforest or TemplateMonster are both good starting points.
> A) its not gonna be good anyway
I couldn't disagree more. "Artistic talent" is not what makes you a good designer, regular practice and passion are what matters most.Check out this thread from conceptart.org forums: http://www.conceptart.org/forums/showthread.php?t=870
The guy starts in 2002 drawing stuff like this: http://attachments.conceptart.org/forums/attachment.php?s=7c... or this http://www.conceptart.org/forums/attachment.php?attachmentid...
And here are some of his artworks after a couple of years of hard work: http://attachments.conceptart.org/forums/attachment.php?atta... http://attachments.conceptart.org/forums/attachment.php?atta...
I'm sure you could achieve the same level of progress in web design or UI design field as long as you are willing to devote enough time for practice.