Funny when one looks at the statistics, but being that so many, many more people die of preventable car accidents and of heart attacks from eating too much junk food, why is it that the same expenditures aren't lavished on those areas?
You go on to say that it's based around the government's desire for "authority" but I don't think this is true - the government is not incompetent or evil enough for this.
I think people are genuinely more fearful of being knifed in the street, intimidated by threatening teenagers, and suffering burglaries, etc, than they are of dying of being obese or in a car crash. You're more likely to die of a heart attack or a car crash than getting knifed by an unruly mob, but it's the fears and desires of the populace that drives policies, not logic or statistics.
I am a big fan of CCTV and the like, but I have more immediate fear for the security of my family on the streets than I do for their health thirty years down the line (sure, I care about that too, but it's not such an immediate "we must do something" type threat).