I hope so! (kidding)
I think aggression and violence need to be kept separate. I know that the definition of aggression includes harm to others but right now I can't think of a better word to describe the 'dominant', 'assertive', 'go after what you want' male spirit.
There is no doubt that testosterone increases the 'male spirit / aggressiveness' which is not a bad thing in my opinion (as long as it doesn't hurt others).
Many guys feel more dominant, confident and assertive when they are in good shape and working out (because they have more testosterone in their body). They do better at their jobs, experience less fear, take more risks and are more confident with women.
It might well be correct that eating meat is one of the causes of 'aggression', but as I've shown said there's nothing wrong with that. Violence on the other hand is rarely justified.