I thought I'm a rhythm guitarist. I don't need to work on that. Or "I have a cool voice. I will just get someone else to play that hard parts." I didn't have a good voice at the time, so I don't know why I thought that would work, and honestly, it's a pretty piss-poor excuse to not get better at something I loved. ESPECIALLY WHEN IT'S SO EASY TO LEARN!
It's a friendly, fun way to get those creative juices flowing. It's also very quick and frees you up from the inventive damn that can inhibit us. It has the potential to hurt some ego, but we must remember that either way, you are winning!