When the Web meets Joe Common
I am a huge fan of content management systems, especially the Drupal system, and have used a number of other systems, including WordPress and phpWebsite. (I've commented on my thoughts on Drupal v. WordPress before.) Content managed solutions seem like the best website solutions hands-down. Designs can be dropped in and out relatively easily, data is held in a database for easy backup, and new features and plug-ins can be added or removed easily.
In the past, most of my development of CMS-powered sites has been for myself. Recently, though, I've been developing a number of sites for Joe Common; regular business people who don't know HTML, don't know the Web, and in some cases, hardly know how to use their computers. Obviously, the biggest power of the CMS is the ability to make it extremely user-friendly, with WYSIWYG editors, simple menus, training sessions, training manuals, category-driven content, and automating as much of the process as possible. And despite all this, things still get messed up. Sometimes the most bizarre of problems appear. It is amazing what can happen when non-technical people start tinkering with technical things.
This really hasn't become a big issue, but it seems like it could easily become a big problem. It seems to me that most businesses are moving toward these types of systems and putting non-technical employees in charge of these highly technical systems since companies decided that it is too expensive to pay a company to maintain a website or to have an internal web development team.
So where is the system really failing? Is it because CMS systems are still too complicated for users? Is it that the wrong people are being put in charge of caring for these systems? (It certainly isn't that these people aren't smart or aren't skilled; their expertise simply isn't in the Web. You wouldn't put your plumber in charge of maintaining your automobile, would you?) Or are businesses in general the problem because they have been convinced by the news media's coverage of the "Web 2.0 Revolution" that anyone and everyone is an expert when it comes to the Web and there's no value in paying someone trained in the Web to build and maintain a website?

I know that this is a crappy answer.. but its all of the above. Content management systems are still complex for beginner / non-technical users, businesses are too greedy to pay a professional instead of someone who will slap something together for half the cost, and businesses have a problem paying a professional to use a tool that is made so that ANYONE can use it.
I am not a great web designer and no where near being an intermediate web developer, but i do know that even i get confused a little bit with some functionality and options in a basic CMS. Present CMSs make things much easier than they used to be, but are still much more complex than a MySpace or a Facebook (which based on popularity and demographic seems to be very easy for everyone to use). I know that MySpace and Facebook don't offer the same package of options as a CMS, but I think the ultimate answer is the continual development/evolution of CMSs till they become easy enough for non-technical users to make use of like MySpace or Facebook. Certainly we cannot wait around for the business world to finally come to the understanding that if you want something technical done you need to hire a technical person because it will never happen.
PS ~ "CMS systems" = "content management system systems" ; )