I don't get what stop words do. I searched for several on the list, and Google returned lots of search results. For example, searching for 1973 brought up 231 million results, with an entry on Wikipedia about the year 1973 in first place.
i think search eingines do not prefer these words and don't give important to a site if these words found
Stop words are those words which are so common that they are useless to index or use in searches. Also Common words or characters that are ignored by the search engine, as they tend to slow down searches without improving the quality of the results. Stop words are reported as part of the query report.
yeah those words seem pointless for me too. most of those words are the word that people will not put when they use search engine. that's why SE wont care about it.