> I'm sure the decision was "data driven" based on real life usage.
This is also how we ended up with the ribbon interface in Microsoft Office 2007 and beyond, then later other places within Windows (Explorer, Paint, etc). Microsoft essentially collected click statistics across various UIs and used those for decision making to choose which buttons would be big and which would be buried under small icons or sub-menus.
I'm used to it now, but it was jarring and took a while.
This is also how we ended up with the ribbon interface in Microsoft Office 2007 and beyond, then later other places within Windows (Explorer, Paint, etc). Microsoft essentially collected click statistics across various UIs and used those for decision making to choose which buttons would be big and which would be buried under small icons or sub-menus.
I'm used to it now, but it was jarring and took a while.