I'm not assuming they're hitting Ctrl+C.
What I'm saying is the screen that says
VIM - Vi IMproved
version 8.0.567
by Bram Moolenaar et al.
Vim is open source and freely distributable
Sponsor Vim development!
type :help sponsor<Enter> for information
type :q<Enter> to exit
type :help<Enter> or <F1> for on-line help
type :help macvim<Enter> for MacVim help
disappears as soon as you enter insert mode (or really interact with Vim at all). If you're in insert mode, you don't see this. So if you see this, typing :quit will work.Of course, yes. The above commenter mentioned insert mode and ctrl+c which is why I was missing that you particularly were talking about this one screen.
It happens because people don't what they are doing. You assume that they hit ctrl+c, then immediately type :quit, but if they did, then they wouldn't be Googling it. They did something between trying to exit and quit that got them into a different mode.