CMS sites are what they are. A way to allow several people to log into the admin and contribute, edit, add, delete content. Wordpress is a nice way to do this, where everyone is (or should be) familiar with the concept and operation. The "super admin" person can decide what the other authors are allowed to do.
Is it necessary? No. Even if an experienced PHP/MySQL scripter uses Wordpress or any other CMS, they should take extra steps for security leaks and problems with hacker exploits. That's why people with good programming backgrounds create their own sites with their own CMS. They can develop a secure site from the ground-up.
So I think the answer to your question is really a matter of your programming experience, money, and your time. The other issue revolves around your server. Whether or not you are using your own server/web server, or are you running your site through a shared webhost. Is your server secure? How much money are you willing to spend to be in total control of your entire website?
That's why this topic isn't discussed much. One person might have $500 to spend on a website, and another person may have $30K-$50K to spend on their site.
Hopefully this will spark other opinions.