I think you're being a little unfair to kriptonic here, and perhaps being a little confused about causation. You're assuming he's failing because he's a negative person. I would say it's much more likely his negativity is a result of being burned out from too much work and not enough sleep.

Burnout is a good thing. Your body is basically telling you that you are working too hard at something that is not achieving results, and it's time for a change.

kriptonic: I would recommend leaving your side projects on the back-burner for a while. Just work on your day-job, and catch up on your sleep and maybe take a vacation. Once you've taken a break, start thinking about your projects and you might come up with a new direction.

Just because you think your idea is good doesn't mean it will be successful. It also doesn't necessarily have much to do with being good at business. You just need to come up with something that other people want to use.