Leftism seeks to undo most of the values that are distinct to Judeo-Christian religion.
Although images of perfection in people's personal lives can cause unhappiness, images of perfect societies - utopian images - can cause monstrous evil. In fact, forcefully changing society to conform...
Happiness is dependent on self-discipline. We are the biggest obstacles to our own happiness. It is much easier to do battle with society and with others than to fight our own nature.
Also, when you escape a Communist regime, you treasure liberty and you understand that as government and state expand, liberty must contract.