As people engage with many more devices on a day to day basis, applications have moved away from "matching the rest of the OS" and towards "consistency of the look an feel across all platforms".
It's still "consistent", just on a different dimension (app-wise instead of OS-wise).
I know HN favors the former, but I don't mind the latter too much. Especially when products are able to strike a nice balance like Outlook on Windows & Mac.
