Not only does making drugs illegal tend to make them taboo, but people have the right to put what they please into their body.
Cigarettes should be regulated: their production, their packaging, their advertisement can all be appropriately controlled. But they should be available for adults.
Moreover, I am even against the recent raising of the cigarette smoking age to 21. The notion that three years after 18 magically causes a huge spurt of maturity is ludicrous.