I think the problem with non smokers vaping, is they want to vape anywhere. This leads to no vaping signs, which doesn't make a difference to me, since I wouldn't vape there anyway. However, someone calls their local representative tells them about someone vaping in a movie theater, then said legislator/city council member proposes anti-vaping legislation. It goes from no vaping signs, to local ordinances, to state restrictions on sales and eventually to strict regulations on the national level.
Non smokers who vape simply don't have the discipline former smokers have. Former smokers know they couldn't smoke everywhere, so generally won't vape in inappropriate areas.