On a Stack Exchange site, if you are viewing a question, and click Log In to take some action on that question, and you log in with valid Stack Exchange credentials (but there's a step that creates an account on that particular site), you are not redirected back to the page on which you clicked the Log In button, that motivated the account creation in the first place. Instead, it goes to a list of questions on that site, causing the user to lose easy access to what it is they wanted to do. Even the browser Back button doesn't get the user there for at least a few clicks, going through Document Expired and login pages again.
Here's an example: