I don't know if I'd call President Obama a health nut; maybe Michelle, but not sure about Barack, unless he quit smoking and switched permanently to the gum.
I'm skeptical because people so often attribute many of the negative effects of other chemicals in tobacco to nicotine with no evidence (a point the OP hammers home at https://www.gwern.net/Nicotine). Even the FDA seems comfortable with this conflation, as evidenced by their disposition toward e-cigs.
Per wikipedia (https://en.wikipedia.org/wiki/Nicotine) the general medical consensus is that nicotine poses few risks on its own for nonpregnant adults, besides vasoconstriction and dependence.