How is Google different from traditional Library OPACs & databases?
In short, the further away your library search is from these characteristics , the more difficult your users will find the search to use due to different expectations. Trained by Google, their searches are created based on the expectations such features are built-in , lacking any one of them will result in difficulties and poor quality results.
Of course implementing these features means losing control and predictability of searches, librarians don't want to be surprised and for sure they don't want to see a result they can't explain. Being able to do a precise controlled search would enable a searcher to be *sure* he has done a exhaustive search that he wants.