There are three:
Big Government: This country was founded on Tobacco. It was our number one export for many years. The entire Jonestown settlement would have fallen apart had not some enterprising farmer smuggled some tobacco seeds over and started growing tobacco. This country has been beholden to them since. Big Government makes more money off the sale of tobacco than the tobacco companies themselves. While they continue to speak out one side of their mouth about the "dangers" of tobacco, what they really are doing is perpetrating the monopoly tobacco has. Smoking cessation products are useless, and lead to relapse. Thus it is in the government's best interest to keep the smoker either on an ineffective smoking cessation program or hopelessly addicted to tobacco. And since Big Pharma and Big Tobacco pay them to do so, it's a win win for them.
Big Tobacco: Kind of self evident. Every vaper that stops smoking is a revenue loss for big tobacco. Since vaping has shown itself to be a pretty effective long term solution (compared to other forms of NRT) Big Tobacco can't count on vapers to return to the fold. They want to corner the vaping market so that they can either make vaping SO expensive as to be out of reach for many of us, or add chemicals to our vaping liquid so that we simply swap one addiction for another. Either way, Big Tobacco wants to change the way you and I vape. They want their proprietary hardware and e-liquid to be THE ONLY solution that is widely available. Once they control the hardware and the liquid, they can then manipulate the liquid in anyway possible, OR turn vaping into an activity that only the rich and trendy can afford. Haven't you heard? Good health is expensive. Ask Fresh Market, any organic food grower, or Volvo and BMW.
Big Pharma: Selling ineffective NRT lines big pharma's pockets quite nicely. And since the government and society continues to stigmatize smokers, it continues to bring profits. Big Pharma is the third spoke of the rotating door that we smokers find ourselves trapped in. Smoker quits with, pays big pharma, smoker relapses, smoker gets stigmatized, smoker decides to quit, pays big pharma....and so on and so on. Plenty of repeat business there.
These three are an unholy trinity all working together to keep the smoker, ashamed, frustrated and hopelessly addicted to their products until they die.
Vaping breaks the unholy trinity's hold on the smoker and is seen as a threat.
This is why you see government officials treating vaping products as the biggest health threat to face the planet, when in fact scientific evidence continues to point otherwise. And by using bad science and irrational and emotional arguments, they convince the low information voter likewise.