Seems like too few categories, safe or not safe? Clearly this is a spectrum
Categorical thinking is not always because of a lack of nuance or of zealotry or stupidity (which are generally more modern dismissive interpretations). Delineating categories is a useful framing to firmly separate what is on the one hand good and virtuous (clean air), and on the other evil and depraved (polluted air). It's an excellent way to identify when exactly rationalization, submission or complaisance kicks in. Well, it's not as bad as it used to be. It's even worse in xyz country. It's not reflected in the average life expectancy. It's the price we pay for modern luxuries etc... etc... Having firm categories, and these will read as fearful or callous defenses.
Good categories should compel to action. In this case, what can be done to move from Box B into Box A. And then do those things (because Box B is inherently evil).
The real world is grey. For sure. And multiple opposing things can be true at once. Nonetheless, we need to cut through that, and I'm fearful we've forgotten how. The reason our cities are degraded is in large part because we have failed to think in categories, and have rationalized away (categorically) wrong habits.