"From the perspective of an end user. Krunner is the only replacement for Katapult."
You might think that, but Krunner is a replacement of the Run-dialog. If you compare Krunner to it's predecessor (the run-dialog), you would see that it's leaps and bounds better than it's predecessor is. The fact that you decide to compare it to completely unrelated app makes your comparison flawed.
"Second, the point with KDE4 is right on the mark, the application is not available anymore due to the fact that that the underlying system forced an application rewrite."
Maybe you should complain to the Katapult-developer then? Things change, KDE included. KDE-devels are not responsible for every single KDE-app out there.
"If you are saying this, I would guess that you never used Katapult, or Gnome-Go for that matter. "
The complaint was that "Krunner is visually cluttered". It's not. Now, it might be that Katapult or some other tool is even less cluttered that Krunner is, but that does not mean that Krunner is cluttered. Like I said, It's just a textbox.
"Katapult had no buttons"
By default, Krunner has two buttons (IIRC). Does two buttons mean that it's "cluttered"?
"no clickable elements"
Just because something is clickable, does not mean that it's "cluttered".
[quote]no empty space beneath reserved to display icons."
Krunner only has space for icons when you actually type something and it's displaying icons. In untyped state, it's just a textbox.
If you so love Katapult and hate Krunner, then maybe you should contact the Katapult-developer and urge him to port his app. Or maybe you should write one yourself.