Don't you think, you are doing something very unethical? It is an act of stealing other's money and should not be encouraged at any cost.
I'm not sure this can be counted as stealing. He's just uploading 1 million keys that he generates randomly (well sure, there's a possibility it was used before but the potential is so small). We can do the same thing, and we might not even comes to the same list of addresses.
But I don't know why would people use this though, if they want to learn about private key and addresses, there's no need to generates that many.