I think the point he's making is that a lot of the UI elements don't quite look or feel right, kind of like how a lot of Adobe CS apps have "native" dialogues full of weird mistakes.

Sometimes little look and feel things have a huge impact on how people react to apps: I remember (and I could be wrong, it's been a while) pretty much instantly not liking Opera on OS X when I first tried it since it had smooth scrolling turned on by default, something almost no Cocoa apps do.