Doing this correctly was Google's USP. Right in the early days, when Altavista had default-OR searching, searchers did "x AND y" almost as a tic. When you did that in Google, it boasted "Google searches for all terms by default. No need for And!"
People switched on the strength of that alone. Now they've gone to this deeply frustrating method of ignoring hard-to-find words in queries, and compounded it by making your actual search even harder to carry out. For marketing reasons. Brilliant.