It's an ego thing. Over-inflated egos, at that. Most people, more specifically smokers, look at vaping as some cheap novelty, fake smoking, etc. it's almost like they think they're superior to the people that vape. The whole mindset of, I'm more hardcore than you cause I smoke. I've had a lot of older women trash my vaping, all while they suck on their smokes, leaving lipstick stains on the filters.
What it comes down to is uninformed people that don't know jack. That's today's society as a whole. It is what it is.