Doge wasn't created as bitcoin or ether, is more like a funny coin to be used for fun pourpuse, that's why there's no limit mining them as well.
The devs left already DOGECOIN but luckily it is still alive and kicking because there are too many traders sees it's advantage of exchanging bitcoin to DOGE when sending to some exchanges because it has faster and lower fees than bitcoin. And when it was sent successfully then that will be the time to exchange it for bitcoin with lesser fees and it's quicker than the usual way of sending bitcoin.