It's no big mystery that the key to being a great coach is by also being a good psychologist.  The great Scottie Bowman was known to be great at mind games.  Mike Keenan was also a mind twister extraordinaire.  But there are different ways to motivate subordinates.  Many coaches such as Bowman, Keenan & Hitchcock use it more negatively, while a Jacques Demers or Don Cherry will be considerably be more positive & be known as a player's coach.  St-Louis appears like a no-nonsense coach who's honest, will give it to you straight & will try to be fair with everyone.  The way he speaks & takes the time to explain his reasoning reminds me of an intellectual.  Not very many coaches today are like him & if he continues to be successful i wouldn't be surprised if various hockey organizations don't turn their attention towards such coaches. It's hard to imagine not wanting to play for a coach like that.
The comparison to Felipe Alou is a very good one.  He had no time for mind games, he was a thinker & when he raised his voice everyone listened.  He had everyone's respect, especially the players he coached.  The bottom line he was, like St-Louis, a decent & humble person.   How can you not like someone like that?