All the comments that "you can just use X to do Y" is missing the point that Paint just works, for almost every value of Y. No argument, Paint.net is great, snipping tool solves the grab and crop, but for most anything else you need to do in a hurry, you need a quick paint program. It's like removing Notepad: we all know hundreds of editors we would replace it with, from Notepad++ to vim/emacs... but isn't nice that when you aren't on your box, you know the core set of tools that are always there? (In other news, Fedora announces dropping grep, lc, and ls from the distro, in favor of python: "most users are devs, let them write their own tools" they stated in a press release).
Paint3D takes longer to load, and has made the simple... much less simple. While we can all say "Yes, that's the way of tech", it's just not necessary.
And yes, I still miss my 1/8" jack on my iphone. Every single day. And stay off my lawn, you whippersnappers.