The safe drinking guidelines, currently 2 drinks per day, and no more ever iirc, are based on a fatality rate = to the lifetime rate of dying in a car accident, again if my understanding is right.
That is, if you drink 2 drinks or less per day, with the alcohol free days and stuff, your lifetime chances of dying from alcohol related causes are equal or less than your lifetime chances of dying in a car accident. But you still might die of alcohol related causes. The safe drinking guidelines give no guarantee you won't, and some drinking below 2 drinks per day will develop fatal cancers and other illnesses they wouldn't have otherwise.
They may kill themselves from getting "a little tipsy from time to time", that's why binge drinking is considered such a serious issue, and the previous guideline was to NEVER ever have more than 4 drinks per day, I believe the recommended level has now been reduced even further.
There would be a level of smoking, grams tobacco/time, where your lifetime chances of dying from smoking related causes would be reduced to less than your lifetime chances of dying in a car accident.
Tobacco can be used safely in the same way that alcohol could be. Reality is, neither substance ever will be used widely with this regard.
There's zero justification for significant policy difference between the two substances, it's just a matter of pricing them both appropriately for their cost to the health care system and community, which in both cases is high.