The agent caused the effect in question, with or without knowledge, or even possible knowledge. The actual consequences of the statute or rule, including its effects on behavior. The law cannot deter unintential infractions by threat of punishment. Negligent liability would deter as much, with fewer prosecutions. It is difficult to prove the mental state of the perpetrator.
Strict liability induces an even higher level of care than does negligence liability.
Strict liability discourages the kinds of activity that can produce the effect. Deontological Arguments Against Strict Liability Unfairness of punishing bad luck. Murder carries a heavier penalty than attempted murder. Vehicular manslaughter carries a heavier penalty than reckless driving. Others are evil only because they involve breaking the law.