It gets weird when the cursor leaves the box while dragging. Now, when you go back inside, you're still in drag mode since the box did not get the "mouse up" event and you end up selecting and dragging random text.
In the end this does not seem to have mattered. Reddit's hardcore "contributors" are the kind of people who enjoy a challenge, even when it's stupid. I think it even turned into some kind of pride for some of them, being able to "master" an idiotically programmed system.
Myself, I just get so frustrated about the idiocy.