>>40567397
2/2

Add to that that many of the most powerful people with greatest means are often really bad policy-makers - even with great intentions nad best education, they may lack skill, necessary traits of character, perspective representing interests of regular people. In fact, far too many don't even understand issues and struggles of said regular people half as well as they think, seeing it merely as simplified and abstract. Cue "if they don't have bread to eat, let them eat cake".

Example is communism supported by people already living a good life and blind to how that system is absolutely unworkable nightmare for majority of lower classes (they think they fight for) striving for something better but lacking means for. And there will have to be hierarchy, conflict of interests and competition, because both ambitious abd petty people will always exists, hierarchies will always build, people will represent various worth, needs and qualities, want to acquire more - also often stemming from noble pursuits - will guide people. And such systems demand selflessness and sacrifice for the whole. So you end up with a system aspiring to wonderful things but by its naive, inconsiderate of human drives nature forever being cursed to not succeed in practice.

>tl;dr
It's because people with power, and thus unfamiliar with woldview of powerless DO try to forcefully push their vision on the world to save others without understanding them, overestimating their idea and while excusing crimes to get there as worthy of their unattainable causes.