Mathematicians want to be able to produce mathematical proofs of irrespective of whether or not a problem is undecidable. Davis, Martin, Engines of Logic, Mathematicians and the Origin of the Computer, W.W. Kleene, Stephen Cole, Mathematical Logic, John Wiley & Sons, Inc. New York, 1967. I use the 2002 reprint from Dover Publications. For illustration Cybersource Corporation v. Retail Decisions, Inc. did not.