Is the CMO role necessary?

I recently read a post on the Branding Strategy Insider blog about the Chief Marketing Officer role and whether it is justified. More and more companies are moving towards creating this role within the C-suite. While the article makes many valid points about the importance of the CMO in aligning the organisation with marketing and creating a more customer centric organisation, I do believe that creating a "position" that looks after "marketing" restricts it's role and influence to a certain extent. It is a paradox, isn't it?

Consider this:

1. If marketing's true role goes beyond sales & advertising, pervading through all functions of the company, what is the value in creating a single role that looks after marketing? Should this be a part of everyone's role in the company?

2. If marketing's true role is long-term profit and value creation, then don't business unit leaders or Chief Executive Officers play the role of a CMO anyway?

I feel that the creation of the CMO role is mainly driven by the insecurity of marketing to occupy a seat at the table. It is unfortunate that today, companies need CMOs to be proponents of the marketing philosophy - why can't this be embraced by everyone?