Welcome MJW!

Good questions. I'll give you my opinion, which may vary from others. To me, SEO is easily it's own standalone profession. I'm sure many others would agree that just doing the SEO on a site can take up 8-10 hours per day.

IMHO, SEO has two basic parts - The SEO that happens when you build a site, and the SEO that you do after the site is built. I believe that webmasters and site builders should have a basic understanding of SEO to be considered professional site builders, but I don't think that SEO exists from neglect. As you have probably figured out by now, there are so many parts and pieces to SEO that it would be almost impossible for one person to know everything about both web design and SEO, much less have the time to do it all.

I actually think the reverse of your idea that SEO should be removed as a single profession, especially when you are talking about a larger company. I speculate that I am not alone in that only after my sites are built does the real "work" begin. Obtaining backlinks, managing adcenter, adwords, and other pay per click advertising campaigns, and keeping up on the latest information about SEO not only takes some time to master, but sure keeps me busy!

I can build a great looking website with lots of great content,functions perfectly and passes all validation tests. Plus, I can make sure that I do great SEO on the front end of the site (keywords, layout......). But, if I don't do the back end SEO on it (bulding links, running ad campaigns....), no one will ever even see my site!