I am really amazed by people like Linus. Their focus, smartness, persistence, conviction etc really are unbelievable. Are people like him born or develop - nature or nurture or something else?
1) Identify and resonate deeply with developer issues (like Git, Linux)
2) Focus on executing a usable product in a very short time
So combined it's a really potent ability. If he had the personality he'd probably be a really great founder, but he has chosen to open source all his stuff.