I think you struck on an important point. For clients Wordpress is a godsend. If you quit contracting or the client needs to change developers for one of a thousand reasons there's a massive pool of talent that can step right in and make adjustments. I've taken over Wordpress sites and the learning curve is almost flat (save a few weird plugins). Anyways, it's a whole lot better of a situation for clients, developers and productivity in general than the days when everyone had a custom framework that solved the same basic CMS issue.