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.
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