If you believe what Amy Barrett said during her confirmation hearings, the legal process is very simple and mechanical. All you need is a judge who has the self-discipline to follow the law instead of enforcing her own policy preferences. She reads the statute and the relevant legislative history (the latter only when necessary) and reaches the right conclusion. Easy!
The reality, of course, is completely different. Statutes and case law are frequently filled with ambiguity. Legislative history goes all over the place. For every canon of construction, there is an equal and opposite canon. There is plenty of room for the judge to impose her own values on the litigants without ever having to disclose what they are. It is a feature of the system that feels unfair to everyone, but it cannot be eliminated. There is no justice machine–just an imperfect system run by fallible people.
That, of course, is why it is necessary in the confirmation process to ask questions about attitudes towards values and policy that sound irrelevant, and why the nominees generally blow them off.