I think that, fundamentally, the fantasy of ruthless dominance is the main appeal of the game. It's probably not a game for you if that doesn't resonate with some part of your brain.
Curious, I've played MOO2 for 30 years as well, and MOO before that, and my style has always been the egalitarian peacemakers. I build fortress garden worlds and only when someone is dumb enough to declare war on me does the destruction begin. Blockade every system and invade, then build paradise around them and let them in when they promise to behave (their pops convert to mine).
My cousin on the other hand rushes a mass of corvettes with no shield and mass drivers/nukes, and Zergs the galaxy with low-tech barbarians. The sheer variety of viable playstyles speaks to the strength of the game's design.