IMO: The most likely reasons someone would exclude smokers (vs. non-smokers) as potential dating candidates would be:
they don't like being around cigarette smoke (irritation, smell, health concerns w/second-hand smoke)...also, the perpetual SMELL that permeates a smoker's environment (car, clothes, hair, etc.) and other unpleasant traits/effects of smoking (smoker's breath, yellow teeth).
I could add more, but I think those are probably the main ones.
The above aren't issues with vaping, though (as far as I know). So if I had to select one or the other, I'd go with "Non-Smoker".
Also, with "Smoker" in your profile, those Smokers are going to gravitate toward you.
I, for one, have NO desire to be around a lit cigarette. I really can't stand the smell...during or after.
Just my 2 cents. : )