Have a look at your jobsteps before you delete the last one. You can see a kind of jobflow. Each step says: goto next step when successful completed but the last step cannot goto a next step because there is no next step. Hence, the last step says: quit with success
Now if you remove the last step then there is a new one the last step formerly not known as last step. And this step says: goto next step - thats now impossible
So the system says: I will do your job and correct this - is it ok for you?
So everything is fine.
No, you're never too old to Yak'n'Roll if you're too young to die.