I have seen users having trouble with pixel soup UIs. They may not think "This should be in a native toolkit", but they do think "How the hell do I subscribe to a folder in the new Outlook?".

> ironically the only group of users I've found that actually care about native UI, are other developers and Mac purist.

One group of people who routinely carry the can for poor product usability and another who by definition care about the Mac platform; entirely what would be expected.