Stupid employers don't stay in business. No smart employer will reduce their labor supply to such an extent that the cost of finding profitable labor exceeds the profit.
I really find it hard to believe, how you can't see this suit by an employee, smoking, apparently at home, not impacting everthing your employees do.
If tobacco were a banned substance, I would have no problem. Are burgers and fries banned?
In actuality, it has been proven that diet is far more responsible for a healthy lifestyle than smoking....for a later debate.
This is big time....and I think it will go to SCOTUS.