The problem isn't whether the AI is easy or hard, but rather that they are a predictable opponent, and you eventually see how the battles tend to develop in the same way because of that. Player opponents just provide a more varied battle experience, have the ability to work in coordinated fleet actions, and are much better at friendly banter than the bots are. It would be nice to have the option of arranged battles (or voluntary vulnerability I guess) against other friendly enemy player fleets on the PVE server.