To clarify Paint's appeal; in addition to this list https://news.ycombinator.com/item?id=14845533 , if you want to drag a square selection of something somewhere else, paint is probably still the goto app in 2017. If not, it has been for far too long. It's a failure on the part of other image apps. Paint hits a power/accessibility sweet spot.
So MS Paint is to Windows what Vi is to Unix?
That is, no matter which editor you prefer, you'll always end up learning Vi, at least its basics. Because when in doubt, it may be the only viable editor that exists on your target system for sure.