Perhaps it came across that way, but I meant something quite different. I'm assuming that a writer can interpret dictionary/thesaurus entries much more effectively than any current search engine. A search engine relies on a mass of user-supplied data (much of it inaccurate) to approach the same task. With rather mixed results.
It tells us a lot about Google's current 'understanding' of words. But it also highlights a lot of misunderstanding. I reckon you could get a better list of related words by asking the nearest person to you at the time ;)
We're coming from very different sides of the debate. I think search engines are playing catch-up when it comes to keywords - that's why a concept like LSI even exists, and to some extent is a major reason something like SEO is even necessary.
I remain a single-finger typist, but a week would be stretching it a bit ;)