[stan_rogers]

It goes a little beyond content writing. At a certain level of resolution, SEO (the good stuff) and accessibility become nearly indistinguishable as well. So yes, there is a sense in which "real" SEO is merely a matter of writing web pages that give your users what they want with optimal markup, and SEO is probably a bad name for it - except that the people who need it are usually going to be searching for ways of getting good search results rather than advice on how to build more informative, accessible web pages.

[normloman]

I worked as an SEO for years. Quit because of this. "Good" SEO is about good content, good coding, and good usability. But in order to do that, you need great designers and writers. SEO people tended to be neither. My colleagues got into the industry by keyword stuffing and link farming. They were trying, unsuccessfully, to change their specialty after updates to Google's algorithm. We helped sites get ranked, but most of our clients would see a better return on investment hiring designers and writers.

You touched on the other issue: Even if all you do is write and design, by calling yourself SEO, you're attracting clients narrowly focused on their search ranking. That's the metric they're going to judge your performance on, and it won't matter how accessible you make their site if they don't get the #1 spot for "cosmetic dentistry allentown pa." So by selling SEO, you miss an opportunity to educate clients on creating a memorable user experience.