Why do parents or adults treat their children cruelly to teach them a lesson?

Parents that’s not very nice. I felt like my dad and mom were meaner to me than to my friends. My dad gave me the silent treatment for stealing his prized possession that I broke. It was from peer pressure when I was 10. I didn’t even want to do it. He wouldn’t even speak to me or look at me. When I tried to call him, he wouldn’t respond.
It was killing me! I couldn’t take the ignoring. That taught me a lesson. I think the silent treatment is cruel. Another time, was being a brat and mean to my older brother so he acted mean back to me. I threw his stuff because he wouldn’t let me go to the party my friends were going to go to. I screamed at him for ruining my life and fun! And got in his face and slapped him. He threw my stuff to give me a taste of my own medicine and got in my face being ugly to him.
He held me down after I tried to hit min again and told me off for smacking him. He scares me when he got pissed. I was 12. He was 30 or 31. He’s my half brother. My oldest nephew (he was 6 in a half at the time) kicked me for slapping his daddy. Rude.

Adults are cruel to kids