As someone who uses single rider on a regular basis, even first thing in the morning when there is often less than five minute waits, I think going through single rider still saves enough time which would be a good enough reason to me to keep it open. The line doesn't require extra staff to control, or operate it. It's just another line. Even if there is "no wait", the time that it requires to walk through the whole queue feels as if it is five minutes. Being able to do this makes me accomplish a lot in the morning and lets me have time to do other things later. And while, some single rider lines are considered a "shorter" wait, sometimes they are the opposite and can close down as it's been previously mentioned as the day goes on. Which is why I do try to do single rider, even first thing in the morning, because on rides (like Gringott's) it can be impossible to do single rider rather quickly. As it can sometimes be a half hour wait and the single rider line can be too packed to wait a reasonable time, or be closed relatively early in the day.
I unfortunately am home at the moment, once they told me they were not opening it at 11 that day, I decided to move onto other things. Riding Kong again can be for another day. If I cannot do something, I just simply accept I can do it another time. I often have a habit of hitting a few rides and move onto the next park and are able to do a few more within only a couple of hours due to my methods.
