That's because Google has the algorithm to prevent scammers from filling it up with porn sites and what have you, something that the others have fallen prey to.
Not any more tho - google came up with that algorithm first, but that doesn't mean other search engines have been left behind...Altavista still sucks a bit, but AllTheWeb never gives ME any porn/scam sites. It's just as good as google, and better if you're searching for an exact phrase (ie. song lyric, error message)
These remarks are untrue. Google DOES show results of searches for "operation clambake". I just checked and got 5,050 hits.
People have got so used to just using Google they've fogotten there are other great search engines out there too. A search for "scientology" using my favourite (http://www.alltheweb.com) listed pro- and anti-scientology sites on the first page, as well as a special fast-link labeled "Opposing --> Scientology".