Some dont care to realize or get past how they feel.. others just need that control..and will go at any length to have it! they are all different yet the victims pains and sorrows are all the same..
maybe if they were willing to accept treatment and wanted to change they would feel bad..realize what they had done..
but it sounds like ur sisters husband is only concerned with control..he is the man of the house and thats what matters!!

Yes, OP... Some of us do.

My husband never apologized. Always blamed me, saying things like I make him feel like less than a man. Or he was mad (so I should understand). Sometimes he tries to convince me that events did not unfold the way they did, that my mind plays tricks on me. Anything but admit he has a problem. Best thing I did: dumped him.

I think the abusers ability and willingness to change depends on whether or not they do feel compassion for how their abuse affects someone. Even if they do want to change it is not something they can just "stop" when it is brought up to them. I am learning this the hard way after many abusive relationships, or I HOPE I am learning it. Yes I told my ex he is like a sociopath because he seems to have no feelings for the hurt he causes (usually).

I think since most abusers can justify their actions, its almost impossible for them to see, or care about how they treat others.
They do pick and choose who to abuse though bec there are certain folks who they wont test. For example their boss, bec they know they will lose their job.
They jack with whoever they percieve as easy targets.