Cigarette tobacco is cured differently from pipe and cigar tobacco. The method is called "bright" curing. Bright cured tobacco provides its chemical effect to the brain in about .7 seconds after inhaling. A sharp, quick draw provides a stimulant effect, and a long, slow draw provides a calming effect. So here you have the "perfect" drug--generally affordable, so no need to turn to a life of crime to use it; easily self-administered; the user subconsciously smokes it in a manner to provide the desired effect; near-immediate results; and it typically takes decades for it to do you in.

The aromatic ingredients in many pipe tobaccos usually do much more for the pleasure of the bystander than for the smoker. I'm not sure what the reasons are, but surely the tobacco companies have decided that aromatic cigarettes won't fly, sales-wise. They've certainly tried all manner of things to increase sales.