Re: ...used to be a good search engine
"This is another change that adversely affects the accuracy of google's results (in the broad sense, including adverts)."
But the only people who care about the accuracy of Google's adverts are the people paying for the ads. People using Google *as a search engine* just filter the ads out (mentally or otherwise). All *they* care about is accuracy in the non-broad sense.
"Room is opening up for a new lean, mean search engine that focuses on giving accurate results (a bit like google itself used to do)."
Sadly, whilst the demand is there, I don't think any room is "opening up". Google's decline in search performance is not due to Google using poorer algorithms than 10 years ago. It is due to the rise of an entire industry bent on subverting *whatever* algorithms anyone uses. The search engine most resistant to SEO is wikipedia, but you can "game" that as well (El Reg passim).