I actually disagree with you guys entirely... look at the game engine...
most of the technology is war-based.

Once you've played a bit, the buildings all take DAYS to build... surely you're not suggesting the game is designed to pop on for 5 minutes a day to choose what to build then leave?

There's one thing you can do all the time.. that's attack things.

Now, if the NPC cities were either more valuable or less fortified, that'd be one things, but other players are by far the richest prizes... why would you NOT attack them.

Even one of the posters lauding peace says their army was out raiding