Many illegal driving behaviors are considered "aggressive" by law enforcement because they demonstrate a

I believe the answer is: Disregard for the law

A behaviour would be considered as 'aggressive' by the law enforcement if it threaten the safety and civility that has been maintained by an established law.

Careless Driving behaviours would definitely endanger the safety of the civilians near them, therefor it would be considered as an aggressive behaviour.

Disregard of the law.

Explanation:

According to the National Highway Traffic Safety Administration (NHTSA), aggressive driving is the running of a vehicle in a way that threatens somebody or someone's property.  The driver usually feels justified in bullying others and pushing people out their way follows.

Aggressive driving behavior ca be making an unsafe lane change, or tailgating and ignoring traffic controls.

it is a better alternative