I agree that the execution isn't very good, but I'm not quite sure if the "failure to execute" is really the core issue. The way I see it it's more like... a mechanic built on a bad idea, namely that the opinions of a leader should be, for the most part, based on a semi-arbitrary part of your empire instead of actual diplomacy. The way Fear and Respect work seems more like a mechanic for a complex board game and way too abstract to fit the roleplay-ish elements of 4x games.