Surely you must concede that, in this particular instance, it's clear-cut that the workplace culture is toxic, and that there are a couple of orders of magnitud

Surely you must concede that, in this particular instance, it's clear-cut that the workplace culture is toxic, and that there are a couple of orders of magnitude in severity between it and this hypothetical non-smoker-excluding office. Surely you must also see that the described behavior is discriminatory. "If they just didn't hire people like X, there wouldn't be a problem" should be a huge red flag, the kind that suggests in a "there be dragons" sort of way that employment and non-discrimination laws might possibly frown upon something here. Surely?