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?