I agree with your conclusions on a personal level.
Second Response... first I wrote an article a few weeks ago on word hijacking. Near the bottom I go over a strong motivational reason for the War on Drugs, that is applied to a lot of other victim-less crimes as well.

I am going to approach this as ASKING some questions, then providing my observations, and hypothesis.

Does the drinking age stop under age people from drinking?
In my personal experience under age people seem to have almost no problem getting alcohol. They also seem to be excited by the fact they are doing something they should not be doing. They have alcohol so they better drink it all while they have the chance. This has been an observation I made as a child of alcoholic parents who became rather anti-alcohol (not at all that way now though I don't personally use it). My answer was never that they should ban or destroy alcohol. I was always more at war with the perception and choice of how it was used. I once gave a speech where we had to link it to something we saw. I was in college and heard two people talking. The conversation basically went like this. "I got so smashed at that party last night I woke up in the bathtub", "cool I wish I was there". In my speech I told people that this basically translated to "I lost total control of myself last night on alcohol, can't remember much else, and woke up uncomfortable in a bathtub", which was admired by the other person and they expressed a little bit of envy. My observations have lead to the personal hypothesis that banning and restricting things can make things more appealing. People like to be able to make choices. They do not like it when other people will not permit them to make their own choices. So, I do believe this IS a factor in the War on Drugs.

If a so-called crime has no victim, is it truly a crime? If so, why?
My honest OPINION is that if there is no victim, then there is no crime. People need to be able to make choices and be responsible for the consequences of their actions. We need to stop viewing PRE-CRIME as a solution. We should not be stopping or arresting people for things that MIGHT happen. We should instead go after them when something happens. If I am stupid and choose to use PCP (aka angel dust) and I don't flip out, so be it. If I choose to jump out of a window and I die. I have already paid the ultimate price, you can't penalize me further. If I harm a person there are already laws in place for assault, and for murder. Use those. If I harm property, or steal something there are already laws in place for property damage, and theft. Use those. I purposefully picked a pretty scary drug for this example.

Should we be banning anything? Does banning work?
I am of the personal opinion that taking choice away from people for what MIGHT happen is not actually my right. People need to be able to make choices, and be responsible for the consequences. I MIGHT trip walking on my side walk, life has dangers. Someone using something banned be it a drug, a book, or a gun MIGHT hurt themselves or someone else. Yet there is danger in simply crossing the street. I do not believe they should be charged with any crime unless there is a victim.

How does the prison system benefit from all of this?

• Subsidized by government
• Labor at less than $1/hour from inmates
• People talk about overseas sweatshops, without realizing we have sweatshops producing ALL kinds of goods, and doing tech jobs as well using inmate prison labor. The same thing we complain about with regards to overseas sweatshops should also be targeted at the prison industrial complex.
• Huge money, and huge lobbying money applied to our government representatitives
• I talk about this with more specific personal examples of dealing with this first hand in my WORD HIJACKING blog