Because Football is more stimulating; with fishing you can be sat around for vast periods of time with no guarenteed sucess. However, with Football goals or pieces or skill are inevitable, a crowd can cheer on their team, where as fishing is very serious and quiet. Football is more family and community orientated whereas fishing is a very secluded and in my opinion, a boring sport if it should even be called one as its not too strenous mentally or physically.
