Ok, that makes sense. I use vim only on Linux, so I wouldn't know. Ctrl-v in normal mode is what always does this for me in terminal vim, but I guess it might interfere with clipboard shortcuts on other platforms.
(Then again, the argument sounds as that vim loses because vim has this different across platforms, while, Notepad++ wins because, well, it is not available on some platforms. In Linux desktop environments, alt+drag typically drags the window and is not passed to the application.)