Our level of aggressiveness or whimpiness is a choice, and there are ways to be aggressive without overdoing it, and surely the more aggressive we are, the more we run the risk of overdoing it in one way or another.. yet I doubt that being aggressive is a negative because we are able to tailor it to our own aspirations, and try to keep in mind if we might be pushing the boundaries too much in terms of starting to have negative consequences associated with our level of aggressiveness.
You are absolutely right, aggressiveness itself is a negative energy that brings in bad results, which can damage an individual lives.
Though aggressiveness is an emotion, which can be control by an individual if they don't want it to escalate, because if not control or balanced, it can affect in different areas of life like relationships, work etc.
Also, having self-regulation can help in adjusting their emotions or balancing to prevent any negative things that will be caused by aggression.