Why couldn't Disney make more new episodes of Kim Possible?

Disney should make more episodes of Kim Possible, Where Shego is destroying a City, and Kim Possible most become a giant, to stop her. That would be a cool episode In Kim Possible. And if we see Kim As a giant and Shego is shrinking. After Kim Possible wins the match over Shego. Kim could use a shrink ray gun to shrink Shego. But the episode should start with Dr. Drakken and Shego are stealing growth machine and they want to test it on one of Dr. Drakken's bad guys. And when Kim possible, is trying to destroy he's evil plan, she's not careful with the machine, and the machine changes Shego in to a 50 foot Shego, and she' is destroying whole city.