I still use my mouse with Krohnkite. I even move a window over another, to swap their positions, or change their size with my mouse. It's not like using an auto tiler means no mouse usage.
KDE wants users to use the mouse.
We are not in GNOME here. KDE team does not want users to use their mouse. KDE usually is there for configuration and features, so that users can do whatever they want. I still think in a future the KDE team will implement "proper" auto tiling functionality.
I watched talks and discussions with Nate Graham. And yes, its obvious they don't use auto tiling and don't understand the benefit from it. That's why the compromise they builtin is the way it is. But as time goes on, more tiling fans will arise, even GNOME and upcoming COSMIC have auto tiling builtin. There are working scripts to auto tile.
KDE will have builtin auto tiling functionality. It's only a matter of time.