Natural crap results

Google's natural search results are making disappointment lots of site owners in those days because after completion of BigDaddy update any one see:

- Search results are not constant yet.
- Search results are showing full of off topic rubbish such as wrong page from an authority site or just the home page of a site that has a relevant sub page means crap sites in top SERPs.

Any reason why Google search results are not steady and relevant?

Yesterday I read an article and according to this article "Google is trying to make profit through irrelevance". Personally I agree with this article a lot and feel that "what we are searching is not the truth but truth is that we are bound to see what they showing us."