This is a very charged question due to subjectivity, but I'll try to explain why I do not use Dreamweaver, nor do any of the web dev professionals I know.
Even if a web designer were to use Dreamweaver without touching code, that person is responsible for the code that is produced. By that I mean that you can create a professional website using Dreamweaver, but if the underlying code--although functional--is inadequate for some other reason, then you're stuck with code you're unable to do anything about.
I say this because Dreamweaver produces some pretty horrendous code when left to its own algorithms. There are some very important current best practices involving semantic HTML, accessibility issues, and search-engine optimization (SEO) that just aren't being met. (Yet.)