It makes a lot of sense if you start to think about it. With a small group of people working on it, it spreads the knowledge out, decentralizes any authorship or specific authority for credit and makes it easy for the team to simply vanish without a trace since most people are looking for one person, instead of many. Sounds a lot like BTC itself, doesn't it? I wouldn't doubt this was part of the design from the very beginning.
It then leaves the by-product behind for others to pick up and push forward - which is essentially what's happened.