@Ragman,
It is very difficult to say. "Unusual betting patterns" ( in English that means bookies squealing) are thought to be significant evidence of play acting.
It is entirely possible that Mr Romo threw two passes to the Lion's defense because of injuries and that three Cowboys defenders couldn't stop the Hail Mary touchdown despite the ball being airborne for about 4 seconds which is a long time in our form of the game.
Parity is certainly a factor.
Basically it is the colour and the movement, being distracted from life's banalities and miseries, dressing up, being in a crowd, beer drinking, aggression catharsis, profits, conversation stimulation and general management of what is a fractious species of organism living in stressful conditions.
Somebody once said that Mexico used to have revolutions and now it has futbol.