It's all about the experience. As long as you learn from that experience, I personally don't think it's ever a waste of time. On one hand, I'm really upset with myself that I didn't win a tournament or at least increase my Limited rating. I'm also upset that I'm way below the Constructed rating threshold, and that makes me look like a terrible player.
The thing I'm most upset about, though, is that I learned absolutely nothing from my core Nationals experience. From the 3 games I played, I learned absolutely nothing other than luck is a *****.
