I’d suggest that part of the success of the NFL is in large part due to NFL Films. They have created a style over the past ~60 years that immediately invokes a sense of awe of the game and players, no matter how crappy the game or players. Even minutiae was covered as some great revelation and insight into how important the game is (Vince Lombardi examined the frozen field before the 61 championship game and selected ripple-soled cleats! Insight!).
I remember being a kid in school and watching the game films. Apparently, school coaches could get the films easily, and every coach I ever had for a regular class invariably showed one at some point; more often if it was health and PE class. They were more interesting in some cases than watching the actual games, particularly because of the baritone narration and specialized shots (the tight spiral is one we’ve all seen). Everybody watching those films felt everything the players felt, rooted for the winners, and felt bad for the losers.
At any rate, we all watched, transfixed, as one team or another mustered their forces, prepared for battle, entered the field, and fought for glory! Every play battle, every player warrior, was described in glowing terms.
Over the years, NFL Films has grown and expanded their productions, but have kept essentially the same style. The result is a collective mindset among fans that the NFL is the pinnacle of sport, and we all watch to see those images and have those feelings.
NFL Films has been a major factor in the popularity of the NFL. I don’t see any similar effort from the CFL. If there is, they’re keeping it quiet.