He is a native french speaker.
That part is key, just being fluent in the language isn't enough. You have to be a real "Pure Laine" to join Molson's boys club.
It means that the list of candidates deemed appropriate by ownership is pretty thin; especially because the rest of the NHL is also interesting in perusing top management talent out of Quebec... just like they are trying to find the best in the rest of Canada... and the US... and Europe. The age when Montreal got first pick of the best hockey minds out of francophone Quebec before everyone else is long since gone. That means limiting themselves to just searching Quebec for their GM and head-coach results in having a far shallower talent pool to draw from; hence you get incompetents like Bergevin who get hired and kept, even as they run the team into the ground.