so it must be doing something rightConsider the fact that when the US was colonized, the native population was small and had a significant technological disadvantages - also true to some extent for central/South America. That gave the colonists a whole continent for virtually free, whereas in their territories of origin they would have had to compete with large incumbent populations that had similar technology, from weapons to the administrative organs of states.
If youg et a huge resource boost you will surely find ways to profit, just as if you received a billion $ to play with. But getting thins for free - especially land - also means you can afford to care less about externalities, because you don't have as many neighbors or you are not jammed as closely together. And so it's easy and natural for people in that situation to prioritize resource extraction and profit maximization. California's gold rush is a relatively recent example of the same phenomenon.
My pet theory is that when you do this on a continental scale, you end up with a culture that defaults to thinking of economic inputs as infinite, and even if they're not, to maximizing output for as long as possible and then moving on. It's slash-and-burn agriculture's mentality (with a side dose of captive labor) but on an industrial-technological scale.
Fast-forward to the present, and there's an awareness that the civilizational free lunch is over, resources and livable territory are finite, and pollution has a nasty habit of ending up somewhere, but where it's still profitable to do business with the attitude described above. A lot of the bitterness in contemporary politics is due to the economic calculus being increasingly obvious thanks to widespread availability of scientific data and network infrastructure.
Incumbents and wannabes whose economic interests/preferences tend toward extraction of resources or rents cannot publicly admit the validity of data about the downsides of their economic activity, because then they would also have to admit that they simply don't care and prefer making money in the short term to any sort of sustainability in the long term. Though numerous, they are too few in number to sustain such a position in face of broad opposition, so they maintain a set of policy arguments (and a polity) based around different but more emollient axioms. The more questionable or untenable those axioms, the more fervently they must be upheld, to maintain the support of their polity.
In the US, the hardline extraction position has a significant overlap with Chrisitan Nationalism, a belief strongly held by ~10% of the population and accepted/supported by another ~20%. The CN position, when you get down to it, is that mankind was meant to exert total dominion over the Earth by divine fiat, and that in the not-too distant future the divine power will return and re-establish itself on earth following a period of apocalyptic upheaval.