I've heard it suggested that it's a good idea to separate design from content and that Web Designer does not promote this separation.

This idea is relevant in technical worlds such as programming, but is not applicable, or practical, in the world of design-led solutions.  (The idea was invented by programmers, not designers!)  Websites are no different from any other visual media, such as TV, advertising, posters, brochures or flyers.  And for any such media, what you say in 'the content' is absolutely tied to how you present this (e.g. the photos you use, the colors, the text, even the style of writing).