There are some women whose boyfriends literally treat them like dogs but they remain with the guy anyways, the attitude and behavior of these men are terribly yet these women decide to stick with their boyfriends because they "love them". How can you love someone who treats you so bad? Any insights?

Ask their fathers! If their dads treateed their mothers like sh1te then there is a chance that the female offspring might like the "bad boys", particulary if the father has other redeeming aspects to his character.