At the risk of going back on topic—
Alliances are really important to my continued interest in the game. This thread (after the negativity up front) settles into a theme where a great many players say they keep playing, intensively, because of their alliances:
A general observation: all primates, including humans, like to form social groups. Dunbar’s Number (about 150) is the largest stable size for real-world social groups, but Dunbar also notes that smaller sizes, about 30, are common in some settings. My guess is that in an internet setting, the Dunbar number is about 30–just the same size as an alliance. Chance?
Personally, I like having a group of allies (dare I say friends?) with whom I can boast about victories, complain about defeats, and generally chat about the game or whatever. We share tips, theorycrafting, strategies, etc. that add to my understanding and enjoyment of the game.
It also helps that we have great leadership that sets and enforces clear expectations with humor and grace.