We might be producing more pollution than before, but at least is isn't as harmful as the ones used in the Industrial Revolution. Back then, there were NO regulations for it. Entire ecosystems would die from it and when you pump things like mercury into the atmosphere, you can harm people.
At least these days it's CO2 gases and a bit of radiation (Nuclear Plants need a fixing. They don't melt down at the drop of a hat.)
Uhm... I see what you mean, but sorry, I disagree with your conclusions (CO2 it is not even pollution to me, it's my breath. Modern industry pollution is something else...). But it is perfectly fair to me that people have different opinions than the one I have, and I respect them the way I wish mines to be respected.
Anyway, I think we are going off topic, so let's go back to the game mechanics. The way I see it, we have 4 civic (ehm... I'm watching The Simpsons

lol):
- Free Market (Mongomery Burns): profit as the priority
- Environmentalism (Lisa Simpson): life quality as the priority
- SP (Skinner): low maintenance as the priority
- Mercantilism (Lovejoy - don't know the spelling -): I won't let you have profit while I do, I'll make my profit by myself and hope you won't so well.
Before BtS FM and SP were the more popular choices, and I guess to be right saying the strongest ones. Mercantilism in BtS gained some popularity for the corporations effects and with a SE in some cases could be really good; FM gained a reduced maintenance for corporations, to balance with SP new features about corporations. ENV didn't get any good bonus (some small bonus about Windmill and Forest Reserve, but nothing important) and corporations costs are even more, so this civic really needed a good reason to be choosed, other than the UN resolution.
Increasing the pollution in game makes the health bonus more valuable and in game mechanic terms the game more balanced: if you choose other than ENV you gain something at the cost of a reduced health, which is now more influential since the unhealthiness is raised compared to warlords. I think they improved the game mechanics this way, and I'm happy with the choice they made.
In conclusion I think factories aren't nerfed, but to get their bonuses in production now you must deal with:
OR a reduced health (since the bigger unhealthiness generated);
OR adopt the ENV civic (losing FM or SP or Mercantilism bonuses).
yatta77