For a couple of decades, scroll bars on windows have occupied a small strip down the entire side of a window. Always conscious of wasted space, Unity's designers have reduced scrollbars to a thin color strip on the right side of the window. Click the strip, and you have an Up and Down arrow to click, or drag for a quicker change of screen.
The Launcher in Unity does even better than the windows, doing away with scroll bars altogether.
Instead, as the Launcher fills with icons, the bottom few are displayed collapsed. Without any need for scrolling, you can count the number of collapsed icons and, in the case of the top one or two, even distinguish their icons. When you need to do, moving the mouse over the collapsed icons will restore them so you can click on them.
Except for a few experiments like Google's Chromebook or some of KDE's widgets, online resources are usually not integrated with those on the local hard drive. You open online resources from within a browser, which makes their source very clear.
By contrast, in Unity's Music and Video lenses, you can either search the contents of your hard drive, or else view or download items online.
Admittedly, in the case of the Music Lens, this functionality is part of the invasion of the desktop by commercialization. However, if the online sources were editable, it could easily be used for free downloads as well.
Preparing this list, I discovered something: most of what I dislike in Unity is based on high level conceptions (for instance, the way users are supposed to work), while much of what I like involves centralization and simplicity in the details (especially rethinking the widgets used for the basic interface).
I now believe that, conceptually, Unity takes several wrong turns, but, in implementing its basic conceptions, Unity has frequently been more innovative than most critics have given it credit for.
In other words, while some of the attacks on Unity are deserved, they don't tell the whole story. No matter how strenuously you object to Unity, as a whole it is an effort at innovation that only happens once or twice a decade in free software.
The degree of innovation makes it worth looking at, even if many of its innovations turn out to be failures. The danger in focusing only on the shortcomings is that the free desktop as a whole may miss the chance to gain some minor but useful innovations.