Not saying you can just template every site. There are some projects that need to be built (designed, and programmed) from scratch, but the average business website is pretty much minor variations on the same 5 layouts, because they work. We've gotten it down to a science of eye movements, how long people stay on a page, how much is too much to read, organizing information and content, where navigation works the best ...all the way down to preferable colors, and font styles.
How many times do you see a site with the logo at the bottom? Or on the right? Top left is where everyone puts it now. Because it works there. Or right side navigation? It's rare. Cause left side or top navigation works. When is the last time you saw red letters on a yellow background? Huge fonts. Fonts too small? Moving gifs? Dancing bananas? Flash openings? We don't do any of those things anymore. White backgrounds are the standard, with the exception of creative and entertainment sites...it's pretty much universal.
Look around at any website, whether it be a bank, or a record company. The basic structure is the same. The only difference is what cool ways you can implement the functions, graphics and images.
Sounds boring, and it's still not easy for the lay person, and there's obviously a little more to the whole thing, but we all follow the same basic structure. How many times do you need to keep building the foundation from scratch?