Corporations allowed to limit liberties?

I think that it is ok for corporations to refuse a job applicant because of smoking if they want. While I do have sympathy for smokers because I know it is an addiction and I know that it would be very difficult to quit, it does not benefit the company to have employees that smoke. While you may call it discrimination, smoking is a choice, and although often the choice to smoke has usually been made long before the smoker applied for the job, it is still a decision, not a disability. If I were the head of a large corporation, my goals would be to make the largest profit while maintaining integrity by treating my workers well and by trying to not harm the environment. I would not want to hire workers that smoke if I had the choice because it has been shown time and time again that smoking increases the risk of cancer and heart disease. Since my company would be providing health insurance to the employees, I would want to hire employees that do not participate in activities that would harm their health. I do not think it is alright to discriminate based on a disability that someone is born with, or race, or family history, because these are not things that people are able to choose. Smoking, however, is a choice. Smoking is terrible for your health and by choosing against it in the workforce, it will provide an incentive to quit. While you may argue that it is your right to smoke, it is also the duty of our government to promote the general welfare. The preamble to our constitution states, "We the People of the United States, in Order to form a more perfect Union, establish Justice, insure domestic Tranquility, provide for the common defence, promote the general Welfare, and secure the Blessings of Liberty to ourselves and our Posterity, do ordain and establish this Constitution for the United States of America." By choosing against smoking in the workforce, corporations would not be imposing limitations on liberties, but rather promoting the general welfare, not only for the non-smokers, but also for the smokers by empowering them to quit a habit that is harming their health.