"It is better that ten guilty persons escape than that one innocent suffer" is a value statement; in the US, some folks agree with it, some do not.
Under your argument, folks who disagreed about that value statement shouldn't bother discussing criminal justice policy; I think that's erroneous and part-and-parcel of Don't Bother With Those People.
Yes, _some_ policy conversations might be futile if folks have completely opposed values, but I don't think we should apply that generally.
We MUST work with people who hold different values than us, without trying to change their values so that they become part of Us.