I think you are oversimplifying things. People comprising the government are not "just" people. They may have personality traits that compel them to seek out

I think you are oversimplifying things. People comprising the government are not "just" people. They may have personality traits that compel them to seek out high-power positions. They may suppress their natural good intentions because where they work, "things are done that way and everybody does that". After several years of such cognitive dissonance, they may just completely change personality-wise. &c., &c.