If regulating what employees eat, sleep patterns, driving record, etc. can enhance the bottom line such regs will no doubt be implemented. Political reasons have absolutely nothing to do with the decision, it's the BOTTOM LINE. And, with unemployment at the current rate, employers have lots of applicants and so can abide fairly severe requirements. If the world ever gets near full-employment and jobs go begging, the situation will self-correct. Today, there are many applications for few jobs so the job hunter has no leverage.
We, on the other hand, can exercise our choice and seek employment else where, or chose not to do business with such companies. If it's the closest hospital and you need emergency treatment you should prepare yourself to suck it up, control your righteous indignation and avail yourself of their services. Or, should you wish, find a quiet little corner to die in.
Smoking is treated as a choice. Smokers are not a protected class. We can work, we can smoke, it is just that sometimes we cannot chose to do both. It's a choice to smoke, not a necessity. It's a a choice to work or stay idle, at least these days it seems to be. If you desire employment at a "no smoking, ever" business you will have to make a change in your life style. Your other choices are to seek employment elsewhere, self-employment or idleness.
As an aside, most doctors working in hospitals are not employees of the facility.