In the past, I've used VS for editing PHP, which I then deployed to the server using a keyboard shortcut.
I understand what you're saying, but I want to point out that VS can be used as an editor even when the target platform isn't MS.
What I'm curious about, is it so good an editor that people commonly use it for general text editing for non-code text? I know Vim and Emacs gets used like that a lot, maybe Notepad too.
The startup time is too long for off-hand editing (I suppose this is hardware dependent). In that case, I'll open Notepad for quick to-do lists, or vi for non-line-ending-mangling tasks. It's pretty unusual for me not to have VS running, though.
I wouldn't start up a VS instance just to edit text, but if I have one running, it's my editor of choice.
I'm curious, does anyone use Visual Studio for non-code editing? For example, I'm typing this in Vim right now. I use Vim for lots of meant-for-human-readers text.