Doing well in SEO may not take a lot of work
I think it is a mistake to assume that any level of SEO wizardry is going to elevate lousy content significantly above its own inherent level of performance. A little, maybe, but not a lot. For a while, perhaps, but not for long.
Second, I think it is far beyond the purview of any SEO guy to aver that he can affect the base level quality of that content to any major degree. To suggest that a website merely has to become the respected go-to source for information among all of its peers worldwide in order to achieve top rankings may be true on the face of it-- but how is that to be accomplished via SEO tweaking? It isn't. The solution lies in hiring legions of the best minds in the field and toiling away for years, not in optimizing web tags for low-value content.
Next, I do not believe that any amount of SEO expertise can get your client to the top of the page. Open up any search on any subject and you'll find all the top spots reserved for people paying CASH MONEY regardless of what Google thinks about the quality of their content. For them to piously proclaim that people only need to write fantastically useful content and then push every one of them down to the bottom of the page in order to make room at the top for a favored class of useless (but wealthy) dilettantes is the height of hypocrisy.
Quality and hard work should be rewarded in an appropriate fashion. I just do not agree that Google is the creator or facilitator of that perfect world. So long as any search engine is allowed to put their thumb on the scale in order to favor their friends and people with cash to spend, that utopia is completely non-achievable. The search engine functions and the ad-selling functions need to be divested from one another as a good starting point towards reform.