Not to make this a death penalty thread but given a choice between the lengthy appeals/expense of death penalty cases and life imprisonment . . . life makes more sense from financial and moral terms. Life is either a gift that no human has the right to remove or it's negotiable. If it's negotiable (which we all know is the case) then any BS set of rules is just as valid as the next. That's not relativism . . . it's just the nature of dealing with people and all the BS they believe in.
Mandatory mins are BS. But you are certainly right that judges should execute the law to the extent it can be done without having to interpret the law. Unfortunately, dumb arse legislators write poo law all the time . . . then they get pissed off when judges inform them about the difference between what the law means and what the legislators intended.