Why do some parents threatened to take of throw their kids' stuff away?

I remember one day I didn't wanna go to school and I cried so much because there was this bully in my class that picked and was so mean to me. My dad and mom (before she walked out on us) told me if I don't stop crying, they would take my dolls away (my favorite ones). It killed me. If I cried, they get taken away. If I didn't and behavior I got them back. I hated that but I never did that again. I was about 6-7.
Also they threatened to take my brothers stuff away too if they misbehaved or did pick up their stuff we called our parents mean! Then my dad said, "Well keep your toys off the floor then. If I see it laying around again, they will be thrown away." My parents told us they didn't mind being called "mean" parents and smiled. I threw a fit and screamed but they didn't care and ignored us. That pissed us off even more when they said that.