There are certainly financial motives behind much of the anti-tobacco activism, but I think there is also a large segment of this movement for which it is a religion. You see the same kind of rigidity, dogmatism, irrationality and righteousness in some environmentalists. Good (them), Evil (Big tobacco), poor sinners who need to be saved (smokers) - everything you need for a religion. These people are simply impervious to reasoned argument because they are true believers.
I think you have nailed it. Some of them seem blind and deaf when it comes to facts that directly contradict their beliefs. It's like trying to argue with a drunk.
(No insult intended to people who are blind and/or deaf. I'm somewhat hearing-impaired myself, but at least I listen up when the truith is being uttered.)