How often do you select a menu item or hyperlink without actually opening it?
The only time I use a file manager is to move files around in bulk but with somewhat careful selection. I'd be using the shell if I just wanted to manipulate a single file or something that I could use wildcards for.
So, having to figure out how to select files without opening them is incredibly frustrating in KDE. Fortunately somebody in this thread just referenced the config setting and I changed it. Finally, sanity prevails until somebody decides I don't know what I'm doing and removes the option...