There are various arguments as to whether sexual orientation is chosen or pre-determined at birth. As for religious affliation, yes that would be struck down, erroneously, because of the 1st Amendment. But again, the Bill of Rights sets limitations on GOVERNMENT, not PRIVATE EMPLOYERS. You call me simple-minded (nice personal attack there) when you are the one who fails to see the difference between government and private concerns.
A private employer SHOULD have the right to discriminate. If I were running a business and didn't want to employ Antarcticans, I should be able to. However, any legitimate business would want to employ whomever helps that business to grow the most. So if that means that I ran a business with 100 employees and Martians did the job 100% better than anyone else, then I should have the right to only employ 100 Martians and no one else. I should also, as a private business owner, have the right (since it is my business, not the government's business) to tell them not to smoke or stink of cigarette smoke while on company time because that is unprofessional and they are trying to sell my $100,000/ea widgets to new prospects.
Re-read the article and maybe you will discover that it is a private employer dictating how their employees must conduct themselves while on company time, NOT on their private time. So as soon as their shift ends and they are OFF company property they can light up. But once they return to their shift, they must conduct themselves within the parameters set into place by the employer or they may go find new employment. The 'smoking huts' are segregated areas where non-employees may smoke because these people do not fall under the employment jurisdiction of the employer (hospital).