Statistical text (token) generation made from an unknown (to the user) training data set is not the same as a keyword/faceted search of arbitrary content acquired from web crawlers.
> The problem is that the conversational interface, for some reason, seems to turn off the natural skepticism that people have when they use a search engine.
For me, my skepticism of using a statistical text generation algorithm as if it were a search engine is because a statistical text generation algorithm is not a search engine.