Before this Light Editor was born, I had all light types hardcoded and it was a total mess. For every change I had to change some numbers in the code. For each type! I never realised I'll need that many different light types. So yeah, that's the main reason. Also, I can see on the fly the light effects - when I'm making new type and when I'm placing the lights on the map.
I can't wait to start pimping old maps and making new ones with this.
If you have questions or any other questions, I'll gladly answer them :)