How do I convince my parents tha video games dont rot the mind?

My parents are over protective I guess. They tell me that video games make you stupid and they make you bad and talk back to your parents and blah blah blah. I play video games like modern warfare 2, black ops, and grand theft auto 4. Never have I wanted to join the military, shoot a gun, or even steal a car for no reason. They blame everything on video games. They always take it away for a dumb reason. Sometimes for no reason at all ( they just feel like taking it) And I don't even spend most my time playing video games. Maybe like 30 minutes to an hour. I do a lot of things around the house and do well in school. Some times I just don't understand parents.... help me plox?