Comment by psychoslave

>The expectation that you'll discover bugs and architecture and design problems doesn't exist if you've already agreed with the team what you're going to build.

This is like, there's not going to be surprise on the road you'll take if you already set the destination point. Though most of the time, you are just given a vague description of the kind of place you want to reach, not a precise point targeted. And you are not necessarily starting with a map, not even an outdated one. Also geological forces reshape the landscape at least as fast as you are able to move.