Well, the destruction of Romulus was followed by the (apparent) death of Spock. If Picard had invested his life's work in reunification as e.g. a Starfleet emissary, he might have actually been living there with his wife (possibly Bev) and children (?). He goes offworld to buy milk at the store, and BOOM goes everything. That would be hard to take, I think, and might make one question their place in the Universe.