This seems pretty extreme, but thank you for bringing the concept of Malthusianism ( https://en.wikipedia.org/wiki/Malthusianism ) to my attention. While i'm not convinced that it's likely to be the end of humanity (but rather the results of thousands of compounding factors), the irresponsibility in regards to unrestrained consumerism is something that i see every day, and there is certainly some merit to those arguments in my eyes because of this.
> The answer is pretty simple: we each don't know everything, in fact we know very little (and about many many things nothing really), and we are very (extremely!) susceptible to peer pressure, and we like to go with the flow, and we accept authority blindly where we know little, and so on.
This, however, i'm not entirely sure about. Short of militant disregard for climate change or even the idea that human actions are capable of changing it in the first place, the viewpoints that i've personally seen expressed are more in the direction of feeling powerless and somewhat depressed about the state of things. Instead of outright ignorance, most of the people that i've talked with believe that the governments have largely failed them and the mechanisms of representation that should be in place are only so as far as looks are concerned. For example, lobbying and corporate interests are prioritized, as well as industry development is prioritized over sustainability. In the end, it feels like maximizing profit margins takes precedence over sustainable progress and long term advancement.
Edit: Climate change and all that is just one example, but the fact that many feel powerless even if they aware of what's going on stands for other things as well.
And most of those people that i've talked with have felt like there's little to nothing that they can individually do, seeing as a significant portion of the society is more than happy to live a hedonistic lifestyle that's rooted in consumption. That doesn't mean that we need to live in some dystopian nightmare either, but i'd argue that it's definitely a worthy goal to make the environment thrive first and to focus on a more utilitarian way of life - meat dishes as something to enjoy rather than to have with every meal, a new phone every 5 years instead of every single year, energy efficient hardware (like Athlon 200GEs) for homelabs instead of the latest Threadripper CPUs (unless absolutely necessary), a used but dependable car instead of a new one and so on. And, of course, supporting local and small businesses, as well as trying your own hand at some of that stuff - going out to hunt game, drag it back home, skin it and cook it (if nothing else, that really makes you appreciate the meat you're eating), or even just simpler things like growing your own tomatoes and cucumbers (which are absolutely delicious), where possible.
If everyone lived at least a bit more like that, we'd have even more breathing room in regards to the environment, in regards to resource usage etc., which feels like a good thing no matter how you look at it. Of course, that's probably also unrealistic as far as expectations go.