If wordpress covers your needs out of the box, then you can simply use wordpress. Developers are used when there is specific functionality requirements that do not exist in an out of the box solutions or to avoid the bloat from the out of the box.
I for example would rarely use any out of the box solution. Time constraints forced me to interface into a third party templating engine on my last project, but since I've performed the interfacing I'll be able to rewrite my own when I have the free time to complete it. My requirements are completely customized, so there exists no out of the box solution that would even scratch the surface of my needs, and the excess bloat coupled with time to learn simply removed those as an option. On the otherhand, if someone wanted a forum I'd just tell them to purchase a vBulletin or find a similar free bbs system online. So simply check what you need to do, and if wordpress will fulfill all of your requirements, then I'd suggest that wordpress is the way to go.
Hah yep I've pulled it out of there as well as there is really no need for a comparison link.