Of course I like the episode and of course you dislike it. So much is obvious. ^^
What do you wanna see? Terra Prime is destroyed just like the conspiracy in TUC is destroyed. You are totally right that the PLOT doesn't show us that xenophobia respectively militarism in the case of TUC suddenly declines. But the ATMOSPHERE (which you seem to be unable to perceive) of the respective final scenes IMPLIES (once again, any hyperliteral reading of fiction that leads to "OMG, there are numerous plotholes" is worthless) that the future will be bright.
Is this realistic? Not one bit. But that is not the point of stories! Each and every story is made up and via definition leaves something out. You plot hole folks focus on precisely this, the stuff that is not told, and totally miss the essence of the story. It's kinda like with those Christian fundamentalists who throw Adam and Eve together with dinosaurs but in their obsession neglect to think about the POINT of this story from Genesis. Or, to use a Trek example, those people who endlessly complain about Delta Vega not being a moon of Vulcan or whatever while totally missing the slightly surrealistic, dream-like quality of the Delta Vega sequence plus, once again, the actual essence of the scene. Nobody cares where the planet is, it is a place to tell a part of a story!