This is because government does not have the right to punish people by association. It's an unfortunate consequence of freedom principles: Bad things can happen

This is because government does not have the right to punish people by association. It's an unfortunate consequence of freedom principles: Bad things can happen, and you can work to prevent bad things from happening, but you must be extremely judicious in how you do so or you fall into tyranny. So very often the only thing to actually do is punish those responsible for bad things, sadly after the bad thing has already occurred.