The "addicts" (as you call them) wanted a safer way to ingest the active ingredient in tobacco. Nicotine on its own isn't much worse for your health than caffeine, but having to inhale burning tobacco leaves to ingest it leads to all sorts of health problems.

People figured out that you could heat up a solution of pure nicotine and glycerins to create a mist that is easily absorbed when inhaled (but didn't include the tars, carbon monoxide, or the host of other byproducts of combustion that lead to respiratory and cardiovascular diseases).

Obviously it's not as ideal as breathing nothing but pure, Spaceballs-style "Perri-air" but it's like telling someone not to bother with a massive harm reduction because it doesn't eliminate 100% of potential health risks.

So while the nicotine is likely derived from tobacco (just because it's the easiest source), using a nicotine mist inhaler is hardly the same as inhaling the smoke of burning tobacco.

What started out mainly in the realm of tinkerers and curious people looking for a better way to wean off nicotine or minimize the health risks of smoking has been co-opted (at least as far as the mainstream discussion goes) by cig companies and those who would seek to become their successors.