I would be a lot more forgiving of these things if the player had even half of the diplomatic options as the AI seems to.
How often in history has a small country started a war with their far more powerful neighbor because they had nicer buildings than them and a better trade relationship with neighboring city-states? This isn't a simulator. In the real world governments change all the time. If the real world worked like Civ V, most of Europe would still have warmonger penalties from the colonial era and the World Wars and Italy would be isolated and under constant attack because of their expansion and bad relations with the rest of the world 2000 years ago. There is nothing realistic about this game, even ignoring the immortal leaders.