The optimum is never zero. Not because we like murder and rape as a society, but because we don't know how to make it zero and broad attempts to bring it closer to zero significantly limit our freedoms and worsen our society. Of course it sounds horrible if you're the victim of a rape (and I guess it would be terrible as a murder victim if you weren't, well, dead) that we accept a baseline level of crime as optimal but the fact is that the best way to get rid of rape is to prevent people from having sex. This is an extremely unpopular proposition and it is actually unlikely to be effective anyways, because wanting to have sex is far more desirable than wanting to rape people, and making crimes illegal doesn't actually prevent them from happening.

There are a number of less extreme suggestions that you actually probably hold (more policing, stronger sentencing, etc.) that people actually do support and are not obviously dead in the water but they have the same tradeoffs on a smaller scale. Do we accept, as a society, less crime that also makes it more likely that you will be mistakenly identified as a criminal? Should we funnel more money towards crime prevention instead of, say, healthcare? Going "we cannot tolerate any crime" sounds great but the optimal amount of crime will always be nonzero.

> The absolute optimum is zero.

Define optimum. It would be trivially easy for Apple to make theft at their stores absolutely zero.

How is that optimum though? The same measures that make theft zero would also drive away pretty much all legitimate business. Is that optimum for you?

The optimum risk level is never zero. There comes a point where the cost of averting the risk is greater than the cost of the risk.

Consider my standard example of this: electric power. We insist nuclear plants be insanely safe, making them uneconomic, making us use far more dangerous sources of power instead.