i think it's jealousy and self-loathing. they hate themselves for being unable and/or unwilling to relinquish themselves from their cigarette addiction, and they're jealous of vapers and those who've quit for finding the ability and strength to move on from something they can't or won't step away from.
in just a short three-plus months, i've been made fun of, fought with, and one person just sort of stopped talking with me i believe cos of my transition to vaping - granted, i wasn't really close to or even friends with this co-worker, but it is still odd, nonetheless. on the other hand, there are maybe a dozen ppl at work who now vape somewhat indirectly cos of me, as i was one of, if not the first person at work several years ago to use and be successful at using an e-cig. so there's that...
“First they ignore you, then they ridicule you, then they fight you, and then you win.”
― Mahatma Gandhi