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.)
The whole point of a tilling window manager is letting the WM do that for you automatically. I use xmonad, you can use the mouse to select windows and even drag them around (though the combination of floating and tilled windows is ugly and unproductive). You have to configure everything from a text file with comments, but how is that any different from a GUI with labels and input boxes? It shouldn't take you more than a few days to get used to the shortcuts or define your own. Doing everything from the keyboard greatly improves productivity if you also use vim/emacs or other keyboard-driven text editor for work + the shell.