One of the `stty` settings ( **`onlcr`** ) tells the _terminal driver_ to convert _newline_ (which is actually ASCII line-feed) to carriage-return plus line-feed.
Unix-like systems just write a _newline_ to end lines, letting the terminal driver do the right thing (convert _newline_ to carriage-return plus line-feed).
Carriage-return "goes left" and line-feed "goes down".
When you set the terminal to raw mode, _newline_ will no longer be converted to carriage-return plus line-feed. Lacking the carriage-returns, you get that _staircase_ effect.