I don't know about you guys but when a giant robot monster growls I find him much more menacing than if he says "SUCH HEROIC NONSENSES!!!!". And everybody else seems to angry since somebody always flinches to him when he growls. And Megatron IS the kind of guy that likes to scare people. I don't see what the problem is here. Just forget that you hate Michael Bay and you want him dead and think about this: growling is menacing. Animals do it. Everything wants to do it to show a presence of power and it works. Why WOULDN'T he growl?