One of the studies that I cited there came from the U.S. National Resource Center on Domestic Violence, the Women of Colour Network, which looked at the issue of incarcerating people accused of domestic violence and found that it did lead to under-reporting. That's because in lots of those situations—to oversimplify the issue significantly for the sake of brevity—you have a power imbalance in the relationship, such that the person who is accused of being the aggressor is also the person who's the breadwinner for the family, the person who has the job. You have the so-called abused spouse either at home, maintaining the home and dealing with child care obligations, or having severe limitations placed on their freedom by the abusive spouse.
In order to look after the family, and especially given people's intense desire to protect their children, they're more likely to put themselves in situations of harm or danger in order to maintain the financial resources they need for their children so that they aren't homeless, so that they can feed their children, so that they can make sure their children have shoes for school. Without naming anyone specifically, I can think of some very powerful women I know who have been in that very position, who have let themselves be victims of domestic violence, silently for years, for fear of losing that.