I don't see how offering nicotine (or caffeine, or amphetamine) is morally wrong if it's not mandatory. In fact, given 2 companies that only differ in what they offer - free beer on Fridays for 1 hour or free stimulants all the time - I would choose the second one in a heart beat. Many people wouldn't, and that's their choice. I just don't see how one approach is better ethically than the other at all.