The "anti" side is almost always louder. They tend to be comprised of people who are already organized against other similar ideaologies or products. Take a look at the organizations rallied against us. Nearly all are already firmly established anti-tobacco organizations.
These groups have had decades to grow, securing funding from numerous sources. They have acquired or established research facilities, staffed their offices with attorneys, hired publicists and multi format media designers/producers. They have moved into government circles through agressive lobbying and have secured impressive stores of assests through lawsuits and private donations.
Adding e-cigs to their target list was an easy choice. They may look like a analog, they emit a smoke-like vapor, they sometimes contain nicotine, ergo they must be elimanated. Why let facts get in the way of a good fundraising or lobbying scheme. And look at all the folks willing to give them money, anti-smoke groups, pharmaceutical companies, tobacco companies, etc. Hell, this issue is a cash cow from heaven to the antis. Money from EVERYWHERE!!!
All of this has come to be simply because someone decided that smoking was bad and started to rally a few like minded individuals against it. But once money and power become factors, the beast grew to its current outrageous proportions. Power and money are often acquired through the manipulation of a simple fear. People are afraid of pollution or global warming, they give money and power to the environmentalists. They become powerful and the next thing you know, you can't drive an SUV. People afraid of "second hand smoke", you get massive anti-tobacco groups. These groups then exagerate or otherwise overstate the dangers of whatever fear they wish to capitalize on.
Look at what happened after 9/11 when the anthrax powder scare had everyone in America calling the cops for dusty junk mail. Hazmat teams collecting up Aunt Ginnie's cable bill. The mere suggestion that it was possible caused millions to panic. So what if it was a relatively isolated incident. Doesn't matter that the legitimate targets were government officials. Everyone thought that Al Queda was trying to kill Bob the lawn guy down the road. Companies made money selling biohazard defense gear, politicians passed bizarre safety laws and security regulations.
Capitalizing on fear is the easiest and quickest path to establishing power and funding. By the time that fear begins to pass, it's too late. The foothold has been secured, and getting rid of it becomes a near logistical impossibility. It becomes self-sustaining.
Even after that fear has been proven irrational or misguided, there will still be "true-believers". No argument, logic, fact, or reason can ever dissuade them. And when you attempt to question their faith, they will not counter with reason, they will shout out pre-arranged talking points and crank up the volume and anger.
