Ok, someone has to ask. What exactly is the benefit of turning it off ?
Drag and drop text editing is the bane of all existence. It is evil, immoral, causes cancer, eats the last piece of pizza, dog-ears your comic books, borrows your car only to return it with an empty tank, and says rude things about your parentage. I believe it should be *OFF* by default in all applications.
Specifically:
It is far FAR too easy to have a block of text selected, then do something else (such as moving over to another window to paste the copied text, then moving back to the first window with a slightly-sloppy click) which accidentally (and almost invisibly) moves that text to a different spot within the editor window. You don't realize you've done it until after it's too late and you've hit the "submit" button.
I've had it happen far too often, and I'm quite handy with a mouse. I'm very precise in all of my clicks and drags, yet I've still done it. Imagine what it's like for someone who's clumsy with a mouse.