Eh, the AI in older Civs didn't bother me (particularly 3 and Alpha Centauri, which I think were the series' highest points). Sure, they had a tendency to suddenly attack you without warning or any coherent plan to win, and sometimes even if you'd maintained a good relationship and were much stronger than them, but it made life interesting. Civ 5 AI's more predictable and makes more sense, but it has more of a bully mentality that's not so fun to interact with.