I think a lot of people do know about SEO, far too many don't though, or worse could be having a totally wrong idea about it. Ideally, everyone wants to hire the best in the industry, but not everyone can afford that, so many have to pave the way to SEO with extensive learning, which is fine - but for large corporations, and companies with money to invest - they really need to hire an expert for each job they require in this field.