Because debugging of complex application must be simple. Debug your website application behind the scene even when in production mode in a simple approach. It was built for PHP programming language but you can try it using your own programming language. It was all time free, simple and easy to implement. Just be creative and you can do a lot more with this debugging tool. You can easily optimized your code, reduce debugging time, turn on / off debug anytime you want, make a maintenance work even when in production mode. You can increase your client's satisfactory over fixing your code easily.