Simmons tells a story of one difficult client who wanted her to drop everything and create a quick and dirty website for his latest and greatest project. Her reply . . . was to smile "at him, nodding in all the right places, and when he stopped talking for just long enough I said, 'All that sounds great. When you're ready to give me the content you want to use so I can see what I'm dealing with, let's talk. '" The clients response . . . "'Can't we just add that later, once the design is finished'" ("Reviving").
This brings up two really good points: 1) writing and design have to go hand-in-hand, and 2) it really does help if the designer is the author of the content as well. The fact is that it really does help if the designer of the web site can also be the author of the written content. If the site is intended to be somewhat playful, and you design it that way, it's likely that you can capture that essence as well in the text. An outside author may not have that ability. It's obvious that attempting to design something without content would likely equal failure.
Bottom line: never design without content, and attempt to always be the author of that content.