Why Is The Sheriff So Mean To Mater?

I don't understand. Why must the sheriff be sooooooo mean to a rescued severely abused and traumatized Tow Truck? Mater had an incredibly bad past. Why must the sheriff be so hard on him? Mater is acting out in fear because he is so messed up and was so badly mistreated. If you don't believe me that Mater was, go to the Cars 2 club and read the picks and read the answers. Also, go to the Mater the Tow Truck fanclub for more info.