It's quite common for a developer to do the fundamentals, and then revisit, and add polish where necessary. Besides, wasting time coming up with a solution to every problem is inefficient when the project is open source, and there's likely going to be several others looking for solutions. As the saying goes two eyes is better than one, and in this case multiple brains will always trump one brain when it comes to such a huge task.
in other words, satoshi got the ball rolliing. that was a huge achievement in and of itself. he put enough pieces of the puzzle together to get people working on it to where it is today.
question is: what if satoshi never existed? would we have any cryptocurrencies at all right now?