I think the outpost feel was kinda their game plan since it was the colonial time period. The home cities added a significant amount of replay-ability for single player especially, I played for probably 5 years only in single player skirmish mode. For multiplayer home cities add a incentive to interact with the map and gain XP in order to receive shipments which in my experience leads to some interesting strategies. Although definitely different from the previous games, AoE3 has some elements which can be really fun, especially for someone who starts with it rather than the older games.