I suspect more that Google's focus on being the best general purpose search engine for the general public and its focus on personalization, predicitive search, etc., is behind it.

It takes a different design of index and algorithms to do what Google has openly had as a goal since well before Porat came on board than it does to be the kind of highly literal search engine Google started as.

There's a market for both, and the market for a well-designed, comprehensive, highly literal engine probably pays a lot more per user than the kind Google is focussed on. But it also is much narrower if there is a Google around. (It's also not clear that the web is the highest-value corpus for such an engine; the really commercially successful ones are more specialized and have large, human curated and annotated datasets is specialized domains, notably law.)