If I remember correctly, I think that's how the Content Translation project started -- it was someone's personal project, which got more people and attention because it's a great idea and showed real success.
and Event Logging, and the Graph extension, and Mediawiki Vagrant , and ... and ... Wikipedia!!
but also, some projects that were not so useful, sure. But we learn, move on, we're not the first group of people to make mistakes : )