I read web-tool-related forums and lately I’ve seen several “WordPress-or-Dreamweaver?” types of questions. WordPress is a GUI-like template-driven CMS. Dreamweaver is a hand-code-intensive Web Building tool. I wouldn’t compare them in the sense of “which is better.” I would contrast them because you don’t use them for the same purposes. Understanding that CMS/WordPress is different from Web-Production/Dreamweaver, changes the question from “which is better” to “when to use one and when to use the other.”
You don’t need knowledge of HTML/CSS to use WordPress. You can start simple and create a nice website with very little knowledge. But there is a lot of learning required to fully leverage the possibilities in WordPress. WordPress is template intensive, with lots of themes pre-packaged for you to choose from (customizing them is part of the extra learning required). Then getting comfortable with the widgets and plugins available with WordPress adds to the learnings and the possibilities. You can get up to speed enough to make a good, professional-looking website fairly quickly (if you have good design/aesthetic talents on your side).
You need knowledge of HTML/CSS to use Dreamweaver effectively. Preferably, you can hand-code well on your own, and use Dreamweaver’s features to code and build more efficiently. Dreamweaver lets you build and publish more effectively than, say, coding in notepad and posting with an FTP tool.
When your site display needs tweaking, I think it is still easier to fix display and behavior issues if you have HTML/CSS knowledge and use a Web Coding tool like Dreamweaver. There is some element of “take what they give you” in CMS systems like WordPress. Having said that, you can customize your WordPress site fairly well, but again, you need code knowledge for extensive customization, maybe even PHP, to do this in WordPress. On the other hand, WordPress lets you make fast massive progress getting a complex templated site stood up rapidly (no time-drag doing all that handcoding).
What do I use? I use both. I use WordPress for this blog. For my container site, bobzeen.com, I typed all of the HTML and CSS partly in notepad and partly in an HTML editor screen (earlier in FrontPage 97 through FrontPage 2003, nowadays in Dreamweaver CS6).