We know without a doubt that smoking is bad for our health. We also know without a doubt that secondhand smoke is dangerous for people around us. A person who continues to smoke, knowing the dangers to himself and others, is not the person I want on my workforce. I was a smoker quite a few years ago. I am not now. Anyone who still smokes in the face of all the information we have about the dangers of smoking, is not somebody I would hire.
So I can refuse to hire people who have multiple sexual partners, and refuse to hire overweight people?
We have laws however that very clearly state that you have certian limits to what you can use as a basis for hiring people. Some people very strongly believe racists or sexist views, they cannot use them as a basis for hiring people.
If you have a problem with the smokers, simply show it as a bona fide job requirement they be non-smoker. Prove how them smoking off hours makes it impossible to do the job.
Whether or not you personally view something is stupid is irrelevant. Lots of people feel the same way about ever drinking, about being overweight, about sex lives and even about taking medication instead of praying for healing.
People can choose to do whatever they want for recreation, even if it shortens their lifespan. Lots of people play full contact sports even though it damages their health and the health of others. I'd hate to see the day when someone says "You play football on weekends, you can't have this job" or "You had wine at mass, go get another job"
