What makes you say he's bad at finishing things? He stuck with his startup for 5+ years. That shows a good amount of perseverance.

What makes you say he never dug into the technology he's using? He clearly dug into it enough to release a couple finished products - that's more than most engineers can say.

My guess is that your lack of sympathy is an indicator of having not faced this degree of failure in your own life, else you wouldn't take such a cynical perspective.