I'm definitely in agreement that having some fundamental understanding of other areas of the business is a good thing, for everyone. The point I'm making is you need to be congnizant of where you spend your time and what new skills you invest time developing. I understand HTML and CSS at a fundamental level—I know what they're for and what's possible. But would taking a class in these skills have been the best used of my time as opposed to say, sharpening my skills around positioning or conversion optimization? Probably not. Knowing when to say no and rely on the expertise of others is an important skill to develop.