Because it's part of my calling.
Ever since I used self-talk to talk myself into a better job in 1980, then used it to quit smoking in 1990 - I've wanted to teach my brothers and sisters in Christ how it works and how to use it.
I know there are lots of competitors, but none of the developers openly acknowledge Christ as their savior (whether He is or isn't) or seem to try hard enough (in my book) to stick to Biblical truth in their scripts.
Since I'm sure you're as concerned as me about what you repeatedly allow into your mind, I wanted to produce something you and your children could be confident would be about honoring God.
So, there you have it.