From articles and interviews about the health effects of vaping, I've gathered that there are basically two distinct groups of people: 1) ordinary people, who hold views ranging from skepticism to enthusiasm, and 2) anti-smoking activists who are sure that vaping is as bad as smoking, no matter what.

The extreme anti-tobacco people don't believe in harm reduction. They also battle snus, which is far healthier than smoking and is probably far less harmful than other forms of "chewing tobacco" due to the way it's processed. Rather than seeing fewer health problems from tobacco related products, these people would will stand on principle while people continue to smoke.