Because it's the ingestion of mind-altering substances to achieve a certain goal. Most often this goal is inebriation for entertainment purposes, some times (especially in indigenous cultures) it's a spiritual goal.
> It's a personal choice.
Sure, many times it is. But I think more often than you'd realize it's less of a choice and more of a predisposition. I mean, if some people are born with allergies or giant feet or different colored eyes, would it be too crazy to assume that some people are more easily addicted to drugs?
> Most addicts aren't born addicted and they make the choice to pick up that first joint.
Just real quick, I think you mean joint as in marijuana joint. Marijuana is completely non-addictive physically, in any circumstance. Nor does it kill brain cells, etc. These are remnants of the hilarious Reefer Madness nonsense that the US unfortunately took part in.
> I don't want to make it easier to be a drug addict in this country. [...]
Then make drugs further decriminalized. Marijuana, for example, is not a gateway drug. Drug dealers are gateway drugs. Every drug dealer that I know, except one, doesn't just deal pot. They've got cocaine, saliva, mushrooms, ecstasy, et cetera et cetera. So instead of being able to just go to a safe environment and get some harmless little green stuff, many drug laws force benign drug-users to be around shady, scummy people with lots of other shady, scummy drugs on them.
> [...] Especially at my expense.
See the above comment, and recognize that your hard-earned tax dollars are being brilliantly spent on DEA sweeps of Marijuana dispensaries in California, for example; countless arrests are made and resources used over completely benign drugs. Massive, massive wars are being waged around the world that suck money into them faster than a black hole. I'm not a socialist myself and would agree that Person A having Person B take money from Person C to pay for his/her decisions is almost laughably dumb; but there are far, FAR more money-sucking endeavors in the US than drug addiction care/treatment. I'd take a socialistic addiction treatment plan over 3 million+ Dept. of Defense employees (that we know about), 216,000 "Department of Homeland Security" employees, massive military expenditures, and who-knows-how-many-millions of dollars spent annually "fighting" marijuana and other drugs.
Just my two cents. Sorry for the long post guys.