"That’s why lately the emphasis is shifting away from delivering the most correct answer and towards delivering the most useful answer."

Useful to whom?

Usefulness is a subjective value; what is useful to you may not be useful to me. That's why giving an accurate answer is always preferable to giving a useful one; that way, each person can adapt the answer to her own purposes.

This is pretty insidious, if you think about it. It abandons the idea of seeking objective truth, adopting a standard that is purely relative -- ultimately to the provider, rather than the end-user. The question will eventually be -- if it isn't already -- not, "What do I tell you, that will be useful to you?" but "What do I tell you, that will be useful to me?"