In reply to Alkis:
It saves your belayer having to hold your weight while you rest.
I had something happen to me a couple of weeks ago that has never happened to me in all the time I've been climbing and which nearly had the same effect as the examples quoted in the article. I clipped a bolt on the lip of a bulge - of a route I've done dozens of time - and clipped my rope in. The move past the bulge is quite dynamic and the moment you get the hold above, your feet come off the footholds below. Just as I reached the hold and started pulling over the bulge the quick draw clipped itself into my harness belay loop and as I tried to move up the quickdraw inverted so my waist was now 30cm above the bolt itself. I realised what had happened but couldn't unclip it with my free hand but neither could I reverse the move without falling onto the bolt. At this point I was facing a factor 2 fall which I knew would hurt but was getting tired. Eventually I grabbed the draw with my free hand and tried to absorb as much of the fall as I could. Still hurt quite a lot though!
Post edited at 10:10