OK, I'll do so.
To put it brutally it's because on Hacker News and probably your social circle, there are too many people whose social status and income depends on being clever, or at least the perception of being clever. This leads us to seriously over-index on things that look like science or data analysis, without even being able to see alternatives that in my experience easily occur to the less (over?) educated.
Consider this article. It's actually a good case in point. The article can be summarized like this:
1. In the 1970s there were these modellers who predicted disaster. Lots of very influential and educated people took them uber-seriously and thought the Limits To Growth was proof positive that everything needed to change.
2. The model turned out to be useless and the disaster it predicted never happened, because the numbers it used for natural resource availability were garbage.
3. This major error did not reduce the modellers confidence in what they were doing (this seems to be a common theme with modellers). Instead they just doubled the number of natural resources and kept on going. That sounds rather arbitrary and not like a real fix to me, but alright. The new models indicated that nothing makes much of a difference for decades (until 2020), conveniently making the predictions unfalsifiable on any timeline that the original authors may have cared about.
4. Now a new researcher has published a new paper on these models, which also says nothing useful. We read that the models "aren't terribly enlightening" because we don't have any data past 2020 yet so which scenario we're supposedly in cannot be determined.
5. Despite all the above, the author concludes that "the most important takeaway from these models is that we need to take definitive action".
Wrong! A rational person can conclude nothing from the evidence in the article. Given that we can only judge the models by prior performance, we should anticipate that the models are probably wrong again. Moreover, the model scenarios don't have any probabilities attached to them and are described in sufficiently vague terms that nobody would ever be able to conclude which scenario we actually followed, again, making it an exercise in stargazing, not science.
Therefore, we cannot actually say we've "known for at least 50 years that our current pattern of consumption is not sustainable". We've known no such thing. The conclusions of the article and many of the commenters here seem like motivated reasoning as a consequence - or at least, it's certainly not Bayesian reasoning!