I just wish he'd grow some balls and actually finish a project instead of giving up and moving on to the next thing. Successful startups that start out sucky keep on improving even though everyone says they suck. Aaron seems to move on to the next great idea in hopes that it'll suck less, and it inevitably doesn't.
It has nothing whatsoever to do with cajones! This is a common trait of inventive individuals - they have so many great ideas that it's hard to keep on one track. What Aaron needs to find is his more conservative counterpart to wrangle his concepts into full-fledged businesses when he grows bored and moves on.
I say this as someone very much like Aaron, with a long trail of half-finished projects and a couple that I actually saw through long enough to bring to fruition.