A lot of people are creating TDs and not coming back for the second argument. Because it's life got in the way, they forgot, or they don't doesn't matter to me. A forfeited turn should equal automatic loss of the TD.
Don't get me wrong TDs aren't the most important thing in life, and more often than not I do the TD for the sake of the debate, and not the win. But not showing up for the 2nd argument is rude. It shows little respect for the other person's time or effort into the TD. If you can't make it to round 2 at least have the respect to post something in the comments section.