The professional interface is a complete mess. flat not nested, functionality duplicated all over the place, widgets strewn across the screen like a toddler just got done playing legos. Exactly what one needs when they will be working with it for hours at end.

Contrast with the casual interface, nested, one way to do things, neat compartments for everything. What is needed to gently guide the user through an unfamiliar task they may only do once a year.

And this is ignoring the dark side, the "designer" interface. Where it just has look good functionality be damned. Take note. The big lie about design is that it exists in a vacuum, that there can be an independent design title. Real design is fundamentally a holistic process that has to consider and integrate all aspects. Including deep engineering. A real designer is an engineer with taste, a rare find to be sure.