I don't think search is as simple as grepping a ton of files. Search Google for "movie where people can't have babies" and the #1 result is Children of Men. I think that's one area where Google pulls ahead of its competition is accurate results to vague queries like that and I think you need a lot of collected data from searches to provide that.
For the record anyone who hasn't seen Children of Men, do yourself favour and find it. One of the greatest and most underrated films of the last decade.
Edit: Oops turns out its 11 years old. Better make that the last two decades then. I'm gettin old