That's absolutely true, but hand on heart, how many Web Designers/Developers here really have a say on when they receive content? The chance to build a design around the content would be a fine thing for many of us.
Yeah, most of them think of their website as a online brochure. Unfortunately that's also how most (print)designers think. They've been doing the Lorum Ipsum Dance for years and years.
I've repeatedly had the pleasure of receiving content on the very day of the launch. And yes, it often involves tweaking the stylesheet, or something similar.
That's a common occurrence for myself and many of the designers I work with. Regarding content, we are at the client's mercy, and unfortunately I find their sense of urgency is often nearly non-existent.