People who hit other people in an effort to get their point across. I know my Dad had temper issues and would slap me on the face if I came home late at times or didn't really adhere to the rules of the house and that made me really distrust him because I never really got what I did wrong since he never explained it or the repercussions of me coming home late, other than I was hit by my own father.

You might have better intentions in mind/are too hot headed to think right but imo it does more harm than good, especially with impressionable kids. (Even emotional scars take a looong time to heal).

Also, wife beaters. I simply cannot stand them and jesus christ, if you're weak enough to hit your wife and tell your daughter that you love her a lot; trust me, somebody in her future could carry out similar behavior and she won't be able to come free of it because even Dad loved Mom and did that to her. I know people who have skewed ideas of relationships and continue to be w their abuser, simply because I'm guessing here similar things happened in their household and they haven't really seen what a healthy relationship looks like. You're a shame of a man, if you do any of the above stuff. (Even women are capable of that, I think and likewise holds true for them too.)