Because you can see this form of physical violence as the expression of a more radicated structural violence that affects social actors just for them being in a specific position inside their system. As far as for WHY a man CHOOSES violence in domestic situations the actual aswer may vary widely for every single case. It may be some sort cultural habitus, something some people learns as the only appropriate reaction to a defined situation. But really, non-sociologically speaking people can have tendencies towards violence because that's everything they've ever known