The core of the issue is the confusion of science with morality. The best way to explain it is the analogy with sex education. Consider the following three things: sex, condoms, abstinence. If we characterize the risk of sex as unwanted pregnancy + STD's, condoms reduce the risk of those things by 98%, and abstinence reduces the risk of those things by 100%. If we are going to look at the issue from a purely scientific perspective, with public health and safety as the priority, then the best advice is to teach abstinence + condoms, i.e. to tell people that abstinence is safest, but if you are not going to abstain, then use a condom. The reason some people advocate abstinence only is obviously because of morality. Some people believe that non-marital sex is immoral, and accordingly, their form of "education" is to give you advice informed by their sense of morality, rather than what is necessarily in your best interests from the standpoint of health and safety.
The analogy is near perfect. Sex, condoms, abstinence = smoking, e-cigarettes, quitting nicotine entirely. Again, if the concern is public health and the framework is science, you will advise people to quit nicotine entirely, but tell them that if they are unable or unwilling to do so, then use e-cigarettes, smokeless, NRT's, etc. on a long term basis. Smoking is obviously a health and safety issue and really shouldn't be considered a "moral" issue. I'm sure that organizations like ALA would agree with that in principle. However, the truth is that the anti-smoking campaign, which was originally based on science and was entirely in the interests of promoting public health and safety, relied heavily on using very extreme rhetoric to scare people into quitting. That rhetoric in turn rubbed off on the general population, and now it has implictly become a moral issue in society. And as with any morality, there are no shades of gray. Cigarettes are not merely bad for your health, they are "evil." Accordingly, anything associated with cigarettes - including nicotine - is "evil." They might tolerate NRT's because they don't resemble cigarettes and everyone using them is supposed to taper them off in a month or two. But e-cigs resemble too closely the cigarette anti-christ, and worse yet, most people who substitute them for regular cigs have no intention of quitting.
"Quit or die" is black and white thinking. It isn't science. It's morality.
This isn't about science and public health any more and hasn't been for a long time. Even organizations like ALA, which was once a pioneer in informing the public about the dangers of tobacco smoking, have now eschewed their ethical responsibility to provide accurate information to the public in favor of participating in the ongoing moral crusade against tobacco which has swept society.
It just isn't rational, not any more. And unfortunately, there is little that can be done about it except to hope that e-cigs become so damn common and popular before the government gets around to banning them that it becomes impossible and impractical to ban them.
- wolf