I think it's a combination of things. You like being on the bleeding edge, first off. Secondly, it seems to me that independent developers on Mac are more likely to deliver a quality product. I'm not quite sure why, as theirs is a smaller community than independent Windows developers, but perhaps they're just more committed to providing a good tool, since they explicitly chose to work on a Mac, as opposed to many Windows people who just fall into their domain. There's also the fact that you're more likely to encounter a lower signal-to-noise ratio (as is the case for little Windows apps) in a wider market... there are good Windows apps out there, it just takes more work to find them.

Thirdly there's the fact that many modifications or enchancements you'd like to make can be done through the terminal, so there's no need for a separate app. Therefore only important problems get tackled by apps, and the challenge leads to more useful and meaningful programs.

Lastly, and I don't mean to troll here, there are more gaps to fill in with OS-enhancing applications in OSX than Windows. You describe how you got a program that does something that's already trivial in Windows, and that seems to be the case fairly often. OSX is much less keyboard-friendly than Windows. Then again there are probably more Mac users who are really into getting exactly the performance and customization out of their OS, proportionally, than Windows people.

It is a great mystery!