yeah but a lot of players get yellow carded for no reason. they dont just get it for dissent.
There is nothing wrong with the game at the moment.
They get warnings, yellow cards and red cards.
While your at it, why not take away the offside rule too. That way there will be more goals.
I know where you are coming from though, that there maybe needs to be a better way of dealing with dissent, but a sin bin would be the wrong answer.
When your playing sport, people are very competitive and get frustrated when they lose or if judgements go against them.
A sin bin would just ruin the game and the game would become very unpopular...