I think you missed the message of the post -- sure, the typewriters are ostensibly the objective of the website, but there was a separate, interesting challenge that he enjoyed for, you know, human reasons: it's fun to learn new things and apply what you learned. In this case, it's software development, but it could easily be learning how to fix a car, how to cook a certain cuisine, how to play an instrument.

Sure, the mission is the end goal: having a fixed car, a completed meal, a sonata you can rehearse. These are all good for you, the viewer, to admire. But that's not where the enjoyment comes from for the creator. It's completely empty satisfaction.