While I can't tell you the history of why the decision was made, regardless of what order the CR and LF are sent or physically carried out I have always thought that the visual metaphor makes sense the way it is: enter/execute the command (downward flowchart direction) and then go back to the beginning of the line to wait for a new command. If the arrow went back to the beginning of the line before going down, then every time I press it some part of my subconscious would think that I'm deleting the command I just typed.