[tshaddox]

> I have never heard someone telling their employee or friend "you're underthinking this".

I mean, probably not with those exact words, but isn't that essentially the feedback you would get for almost any mistake you make at work that was foreseeable but not foreseen? Or even things like a code review, where pretty much all comments are of the form "you might want to consider how this effects OtherSystemX," which is a more helpful way of saying "you might be failing to think about something you ought to think about."

[xyzelement]

That's exactly right. Under-thinking is often more obvious in terms of consequences so you talk about those.