Funny thing, strip the nicotine from the terrible delivery system (and the MAOIs it contains) and nicotine becomes much more benign.
But in general, most of the actual harm from drugs comes from the prohibition itself.
Nicotine is a mild stimulant just like caffeine, by far the worlds most used drug. I really don't understand the growing condemnation of nicotine vaporizers. It is like drug court judges who force addicts to get off successful Methadone regiments because of moral opposition to drugs, while sipping on a cup of joe of course.