You can go on forever about how Apollo wants to build a finer world, how he wants to help people and make a better place. But you have to realize, the man terrifies people. He's possibly the only one on the planet who could take Mr. Majestic, another Superman analogue with more powers than the original, in a straight fight and stand a chance of winning. And the populace knows it. They also know that he's killed God, taken over America, toppled dictatorships, and rerouted volcanoes. Even if he doesn't scare the general populace all of the time, world governments are terrified of him.

Apollo definitely belongs in the Sinestro Corps.