Every once in a long while (very long now) you'll stumble across a dialog box that looks like it's from Windows 3.1. ODBC is one of them that's still that old.
It is, but there's still a standard system style that the majority of the apps are expected to use. Which is exactly what WPF uses - it's fairly easy to see if you take a WPF app and observe the differences on Win7/8/10.
In any case, surely, adding yet another different style only makes the problem worse.
Apple also did this whole "our apps are special" thing more than once.
I don't know why, but there's this weird temptation for every app to try to present itself as some kind of unique work of art, when it comes to UX. But I don't want art, and I don't want branding. I just want ergonomic tools - and part of ergonomics is not to have to re-learn everything every time you pick up a new thing.