When I made this report, I looked for a duplicate bug report and couldn't find one. I'm just trying to help, but if you all believe that I am just making duplicate reports to mess up your website, I won't be reporting any more bugs.
@Jonathan The issue is similar, but this is more about how long the launcher takes to close, not the fact it is still open. See Torabi's comment. Part of this bug is also bug MCL-1280 where the launcher remains open after Minecraft quits.
@CubeTheThird I didn't have any setting set for Launcher Visibility
That's fine. Do whatever you want; I really don't care.