I want to be able to drag the windows around to rearrange things with my mouse, not have to remember or look up keyboard shortcuts. The model of dragging things around with a mouse is intuitive and simple. Sure, have the keyboard shortcuts as well, but give us both! If I wanted to have to look up the documentation every time I need to perform the simplest operation with my software tools, I’d use git.
I would love to see some sort of tiling layout manager you could run on top of KDE. (Heresy, I know.)