I didn't grow up on football but that was my impression when I started watching football after watching hockey growing up.
Football plays typically take less than 10 secs to run. A hockey segment can be ongoing for 3-5 mins at a time. Players are changing live during play and they go all out for 30 secs and then get replaced by the next line that again goes all you for 30 secs....
I've never met someone who walked away from a hockey game and said that was boring. Especially with those newer to the game.