The problem is that when attacking people's bases the person has to be offline for you to find their base. Now if you are nexting and get to their base and they log on before you lay any troops down they will still have to wait till you skip their base or attack it. But once you leave it they can have access to it again. The reason your idea won't be implemented is that once they go to their base you clicking the previous button wouldn't be logical as they aren't offline so their base isn't viewable anymore. Yes this example would be rare but I have encountered it a few times and that's more than enough to say it will happen plenty game wide.