No results found is actively optimized against, which raises recall and reduces precision of search results Via synonyms, stop words, etc. the priority of a search engine is to deliver you results because those are actionable even if not fully relevant.
I agree and I like that meta search engines offer fuzzy search matching, because sometimes you know what you want but are not quite sure of the best keywords to use to find it.
I just wish more search engines offered an option or default setting where search results would only include exact matches.