This eliminates the forum of innocence. Therefore, eliminating the fundamental liberty of independent choice. When the lawful are punished for the acts of the lawless, you harden the hearts of society towards the law itself. Hence, you create an animosity, which is acted out. Giving the opposite result than intended - more lawlessness.
Preventive law is just as much an misimpression as having rights.
So when someone breaks this preventive law, the whole society becomes the assailant, not the victim. The direct victim becomes shrouded amongst the constant political rancor. More preventive laws are offered to comfort the loss of the last deceptive law. The argument is made, that it is beneath an advanced society to be only reactionary towards misdeeds. That preventive laws are an advanced measure of security of future offense.