I'm going to make a guess that before 1994 baseball was America's #1 sport. Then the players/owners decided to shoot themselves and decided to cancel a season midway through (thereby ruining the Montreal Expos' one and only chance at ever winning the World Series - it's assumed they were the front-runners as they were running away with NL East and the NL in general) and went on to almost kill baseball as we knew it. I think the strike of 1994 is what propelled the NFL ahead of MLB.