There are people who give exactly that reason... have been, for a long time, far longer than the medical angle has been around. To not support legalization just because of the medical-pot movement strikes me as a bit... phony. Either it's the right thing to do or it's not, what other people say about it shouldn't make a difference.
The war on pot was initially justified by raising the fear that white girls would be seduced by black musicians using pot. The arguements have changed a bit since then, but not much.
OK -- using pot has potential bad consequences for some people.
That is an arguement for not USING pot, and arguement that should be presented to every young person.
That is NOT an arguement for CRIMINALIZATING pot.
Many of us hold two beliefs at the same time without contradiction:
1) Using Drugs, including Pot, is bad.
2) The War on Drugs is worse.
I am past 60, and I still haven't heard a good approach for discouraging vices (e.g., use of pot, tobacco, alcohol, prostitution, promiscuous gay sex, etc.) which do not create worse consequences than the vices being discouraged.
The war on pot has killed more people and destroyed more lives (e.g., due to mandatory minimum sentences for simple drug possession) than the pot would have if left alone and discouraged with education. It has resulted in the formation of a police state, and the loss of rights, the loss of restraints placed on the government by the Constitution. It has resulted in the waste of billions of dollars extracted from taxpayers at the point of a gun. It has resulted in the corruption of the justice system, from cops to prosecuters to judges to legislators.
It is time to look at ways of reducing harm, not exchanging the "use of drugs" harm for another which is much worse.
OK, I'll step up and be brave. I care about sick people, but I also believe that if you grow a plant, be it tomato, tobacco, or cannabis, it is YOUR business how you use that plant. If you bake a cake, it's YOUR cake.
Another thing that bugs me--it's a plant. A Plant. This is ridiculous. This isn't a meth lab. Not the Medallin (sp?) cartel. It's a plant. These people think it will help them. Leave them alone. If someone wants to grow a plant and do whatever they want with it, so be it.
I'd be for legalizing growing and using your own. Why is that a problem?