Search engine woes!!

I find a lot of people talking about search engines. Not about how they make our life easy but, about how bad they are. I feel any search engine works in its own way[ algorithm ]. It is necessary to tune the parameters in the algorithm depending on the growth of web and with the rise of new kind of data getting available. we could only take a probabilistic approach to the NP problem or have new heuristics depending on the data to be searched.