If you are using the application menu, this is now fixed; there is a description next to items, and typing in the search includes searching in the menu; when I search for "editor" it shows emacs, vim, and ecrire (along with a couple other non text editor programs like "palette editor". Searching for "text editor' shows just the text editors; I don't have kate installed, but I assume it would show up here if it were.
Similarly dolphin shows "File Manager" next to it, and when I to search for "file manager" it is right at the top of the list.
I wouldn't have said this is really fixed, I think this is more of a workaround because KDE doesn't want to lose the names of their software. I think that an approach similar to Gnome's should be taken, where it has Files or Text Editor as the main name but if I search for nautilus or gnome-text-editor (or gedit) it will show the correct result. I do agree that it is better than nothing however.
Similarly dolphin shows "File Manager" next to it, and when I to search for "file manager" it is right at the top of the list.