It looks like you are being misled by the bolding that Google is showing in the results snippet. A search for peopleware quiet does return a few results which have quite in bold in the snippet text, but in most or all the cases the page for such a result also has quite in the page text. (An exception is when quiet only appears in the anchor text of a link to the page, which Google deems a hit on quiet for the linked-to page.) The problem is that Google's bolding code always applies the "spelling correction" for determining what to enhance with bold, but this appears to affect only the snippet, not the search engine's decision to include the result in the results list.
If the bolding bothers you, you can use quotes (or, equivalently, a +) on the word, like peopleware +quiet. The snippet will not then have quiet or other variants highlighted. Note that this also has the effect of suppressing matching of synonyms. (For example, imagine song words includes hits on lyrics but imagine song +words does not.)