A Blog vs. a Box of Legos?
A lot of people compare Drupal to a box of Legos or a Swiss army knife. In contrast, most people compare Wordpress to, well, a blog.
As a designer (who has also done some front-end work), my experience is that the decision of which CMS to use depends on what you're trying to do and what type of players you have on your team.
I was able to pick up Wordpress pretty quickly. One of the huge pluses (and this is important) of Wordpress is the independence I and other designers have because we're able to put out a complete site on our own.
But when I needed a particular kind of customization, I started wishing I had access to Views.
With Complexity Comes a Learning Curve
We do a lot of complex sites here at Phase2 and these definitely lend themselves toward using Drupal. Our developers are pros at knowing which lego block in the box is the one to use for a particular challenge. But the idea of creating a Drupal site on my own is daunting.
Recently, there was a big discussion about this on Reddit. It seems there's a lot of passion on both sides (maybe Drupalistas are bit more passionate!).
Which is better — Wordpress or Drupal? Based on my own experience, I think...well, it depends. When the designer is also the developer or when you're trying to build a simple site with a few pages, WordPress is probably the way to go. However, for complex sites that require tons of customization and flexibility, you probably want Drupal in your toolbox.