Indeed, the enjoyment in software engineering may come from problem-solving (for many of us at least) - but that means that at the end of it, you've created something that solves that client's problem; you've built something for them that they're now going to use. The requirements stage, and subsequent refining based on what the client needs to do, absolutely is the most important stage.

> a significant part of that success came from Notch's very active involvement in the community

I've never heard it argued otherwise, although it probably doesn't get emphasized enough. It was very interesting at the time to watch how closely he interacted with the community, asking opinions and listening, while also making them feel involved by being open about the details of what he was doing. It was a massively refreshing counter to the way the big game studios were coming across so arrogantly at the time, being certain they knew better than their users about what the users wanted. Notch's attitude created that community feel around the game, and made you feel unusually close to the development and even the decision-making processes. That in turn led to word-of-mouth advertising that resulted in Minecraft becoming one of the biggest selling games of all time.