[jckarter]

A big difference between iOS and OS X is that desktop applications have more than 20 years of UI research and convention behind them, while touch interfaces have less than half (maybe even less than a quarter) that. There's thus a lot more room for experimentation in touch interfaces since there isn't as large a body of best practices. Apps that try to go their own way UI-wise on OS X are more than likely going to end up subtly violating the norms of OS X application behavior that standard Cocoa apps all follow implicitly, much like Qt apps on OS X do. Indeed, Gruber's example of Twitter 2 already misbehaves in a number of head-scratching ways: among the ones I've noticed, hitting cmd-W from the tweet list hides the entire app rather than closing the tweet window, and the "compose tweet" box floats over everything even when the app is in the background. I think the tolerance for UI annoyances like these is a lot lower, and apps that try to go their own way are going to expose them a lot more than apps that stick to the tried and tested standard widgets.

[zoul]

Good point. One of the main reasons against non-standard UI design is that there is a huge amount of behaviour attached to the standard UI and once you start implementing your own interface elements, you’ll almost never get everything right. Keyboard shortcuts, accessibility, system hooks for other apps, etc.