Neither one is justified. They both have a moral and religious obligation to give or receive a get willingly and immediately. Not doing so is extortion, is cruelty, and is using the brachos Hashem has bestowed (children, first and foremost, as well as resources, time, and kavonoh) as leverage in a petty, materialistic, and vindictive endeavour. Its hard enough to move on and continue to do what HKBH wants of us without this michshol.
There is no logic in thinking that someone (man or woman) kept in a marriage against their will will have any interest in making that marriage work, and the resentment, the hatred, the rebounding of that negativity on children and other family and friends will only grow. Anyone who thinks otherwise is a deluded fool.
When R’G made his takonos I am sure there was opposition to them, yet he did so because it was in the interests of Am Yisroel. If those who are considered Daas Torah want to demonstrate why they are or should be considered so, maybe they could address this issue simply, equitably, and finally in a takonoh of their own. A Horaas Sho’oh, as the divorce rate has never been so high, but the plague of vindictive creation of agunos and their male equivalent has never been so high either. THAT would be leadership indeed.