If people stop voting up such comments, people will eventually stop making them.
That's like saying, "If we start putting people in jail for using illegal drugs, people will eventually stop using illegal drugs." Unfortunately that's just not how it works - some people comment (or use drugs, etc) because they can't help themselves, rather than for karma/recognition/trolling/attention. Idealism is a good place to start but but, long term, you have to recognize it as such.
If you believe this, then what is the purpose of putting illegal drug users in jail?
However I think his analogy is flawed, and that a system that successfully penalizes poor comments and submissions does have a valid societal purpose here, mainly because posting is nowhere near as addictive as most illegal drugs. And for those whom it is - perhaps we can get a treatment program going :)
The moral majority (or a vocal minority with the necessary clout) imposing it's ideas? Bureaucracy inventing roles for itself using some early 20th century myths about drugs? A convenient mean for controlling ghetto populations (like blacks, latinos, etc)? Sheer stupidity? All the above?
In the same way, some people will make stupid comments. But there are also a significant number of people who won't. I know I'm far more hesitant to make dumb/funny comments on HN than on other sites because I know that they won't be tolerated, and will be downvoted.
Just because a system isn't perfect, and won't fix the whole problem, doesn't mean it won't have a significant impact on mitigating part of the problem.
It's not my analogy; that's just drug addiction. If you don't believe in the addiction part of drug addiction, then that's where we would differ, I suppose. I think that drug and alcohol addictions are true addictions for some people (as opposed to just bad habits).
I have to confess that I don't understand how the rest of your comments relate to my post.
The discussion was on using this system to deter people from posting "bad" comments, and you compared this to threatening people with jailtime for drugs.
And under the proposed system, those people will never achieve a high karma score and so never have disproportionate influence over the site. That's precisely why it's an improvement.