Kickoff (and Kicker, can't seem to file under multiple components) have the following two features: 1. "Edit Applications", accessed by right clicking the widget on the panel itself, which brings up the KDE Menu editor; and 2. "Edit Application", accessed by right clicking a specific application (eg. Firefox), which brings up the properties dialog for the .desktop file. In my experience these two very different options are far too similarly named; I always end up pressing the wrong thing.
How can you press the wrong thing when each one is accessed from a totally different place though? The context makes it clear: - Right-click on the icon for the whole widget => edit all applications - Right-click on a specific app => edit just that application I think it's pretty clear.
I wouldn't say *totally* different; they do both take place at the application launcher... You may read "Edit Applications" as meaning "Edit *all* applications", but (frankly) I read it as meaning "Edit applications *of your choosing*." Consider this: if you're on a website for an airline, and you see a link that says "Purchase tickets", you're not going to think 'Ah, this must be a button to buy every seat they have available!', would you? This might just be negative transfer from Windows whose context menu for Start is really a bunch of shortcuts, but perhaps better phrasing would be "The 'Edit Applications' button does not, in fact, launch an app for configuring .desktop files". I hope this clears things up.
This has been largely addressed by making KMenuEdit open in response to both menu items for Plasma 6.3. Beyond that, it's considered intentional at this point in time.