It's not about WordPress, it's more about using a Content Management System for dynamic contents (news, blogs, stuff that are added from time to time and listed in chronological order). If you only have static contents, then Dreamweaver will probably do fine if that is comfortable for you and you are the only editor.
For simple websites, I still tend to use a CMS, a more simple ones like:
there is practically no learning curve at all, because it is so simple. For why CMS, I guess the best reason is the ease of use. There is very little complicated HTML or code to deal with, specially if you have an editor that doesn't know about Dreamweaver or HTML, uploading files, etc. And you can use any computer to update the site, without Dreamweaver or FTP client installed.
And most CMS already has themes, so you don't have to design something from scratch. in Dreamweaver, you still have to deal with HTML code directly and changing contents can be a pain and time consuming in the future (like changing site design, which is a snap in WP).