Without a doubt yes,
SEO is only important if you are trying to get traffic to your page, site or blog.
Some people write hubs just to be writing. They write poetry, short stories and other things of that nature.
But if you are writing to sell products such as I do, or are writing to get advertisement income then you must SEO your work or you will get very little traffic.
This article should help you understand what I do to get my articles read outside of the hub community.