It doesn't sound personal. But I would argue that it's not an example of necessity at all.

Commercial app development is one way that something like this could happen. But just because it's the first mind that comes to mind doesn't mean much. By the same token, someone could point to a commercial app or project that never got finished but was in beta stages and say "this is an example of why open source development would be better - when the developer decides he doesn't want to work on it, someone else who knows how to code could do it by picking up where he left off."

At the end of the day, this is not about open or closed source, free or commercial software. It's simply about the fact that this developer happened to decide he didn't care enough to keep working on it, or had other things he needed to get done. It happens all the time in the commercial app world too. It's just that in commercial app development you don't see it as much because half-finished or beta apps are rarely seen by the public. Even if human beings needed money to have incentive (we have other motivations, often ones that over-power pursuit of money), it doesn't mean having monetary incentive would have kept this developed interested in RotateDaemon.

So basically, maybe money would have helped in this case, maybe it wouldn't have. We don't know what happened in the developer's life. Even if in this case, money would have kept him working on it, that doesn't exactly disprove or prove the ability of open source software to grow on its own or the need for commercial software. There's too many other factors involved that we don't know.