Angry verbal abuse and neglect is way worse than a quick slap on the bum.
My dad keeps on saying "i never hit you guys". Sure, never hit, but he would terrorize the shit out of us via angry verbal rage and humiliation. Also, besides school grades, he didn't give two shits what we did, nor did he partake in active parenting or try to instil in us vital social/life skills.
I see no problem in a disciplinary slap on the bum or a tug on the arm. Also, that shit can't be regular either, like bigcyp described, he uses physical discipline as the last line of defence when all other verbal avenues have been exhausted.
Nancy liberal westerners know fuck all about parenting. Kids are son of a bitch c.unts completely oblivious to discipline and manners.