The problem is that the actual process by which this guesswork is done, actually right now in the real world, is nonsense. It is permeated by intentional distortions of reality. As a result, in my opinion, research is pointed in directions which a reasonable observer would guess are dry holes. The fundamental difficulty is that Congress is not a reasonable observer - it is a political one.
This is inextricable from the phenomenon of official research funding. I suspect that private philanthropic funding - the way it worked before WWII, a period in which there was no computer science, but quite a lot of other science - would do a much better job of "guesswork."