gah, people like that irritate me. if it were sincere--but it does sound psychological. as lynn said, PG is used in some asthma inhalers.
i know that vaping doesn't bother my grandma (who has a CRAZY acute sense of smell)--she actually loves the way my vapes smell.
nor does it bother my grandad (COPD)
or my aunt (constant allergies/coughing). actually, when my g'dad is sitting there doing his breathing treatment (one of the big nebulizers--creates a small amount of vapor), i often sit there with him, vaping, and shouting over the noise of the nebulizer.

his reaction to me vaping? "I hope this keeps
you from having to use one of
these" *indicating nebulizer*
considering they're all what i'd consider high risk to experience annoyance/side effects from vaping and don't, i'm a little suspicious of anyone who does.