I remember listening to an episode of hardcore history about capital punishment, it detailed public executions throughout the ages, and the takeaway is this:
You could literally publicly rip people limb from limb with horses and rope, people are still going to steal, assault, and rape.
If seeing someone getting skinned alive isn't enough of a deterrent, I don't know why prison would be.
Sure, but I wouldn't exactly categorize speeding as an 'evil' act - just reckless.
But then there are malicious crimes. These kinds of crimes are driven by motivations which regularly transcend punishment.