Whenever I see a yeshiva bachur with nice Middos, learning sincerely, etc, I “shep nachas.” However, the second he takes out a cigarette, my entire image of him changes.
Well, maybe it shouldn’t. Maybe you should use that to change your image of smokers. Why do you let your mental image of smokers change your view of people, in the face of evidence that good normal people, who learn torah and have good middos, do smoke.