
Ideological flaws are relative, someone who thinks one way is going to think other ways of thinking are inherently flawed. On the other hand, zealous belief to the point of giving one’s own life could lend a hint of legitimacy to an ideology. What is your basis for the idea that “almost all kind are flawed?”
It’s that idea of a utopian society where suffering is minimal to nonexistent that humans have been chasing pretty much since we established societies, who knows if it’s even physically possible to achieve. As far as dying for your beliefs goes, I’d say anyone who dies in the name of an ideology is generally doing so in “defense” of said ideology. Especially devoted followers will view any attack on their beliefs as a personal attack and feel their own safety is at risk.