my belief is that there is 'probably no god'
It's impossible to prove for certain, without any doubt
So far, no one who has posted has claimed to be a Gnostic atheist so that really makes us all some form of Agnostics. (according to HintofLimes chart on the first page of this thread)
People that believe that there is no God, or that believe that God is wicked and destructive and therefore should not be obeyed, tend to act without regard for God. Without God, they answer only to society and themselves. When they answer to themselves and society instead of a "higher cause", they tend to make better (and usually quicker) decisions. And, if they make a bad decision, they can reverse it more quickly without having to appeal to some Almighty God that is only going to confuse them even worse.
This comment relates to peoples actions. I'm not wondering about that. I'm wondering why it's not more appealing to just admit "I don't know" and leave the door cracked just a little bit. (since we're all some form of Agnostic anyway) Some form of hope for the possibility of something better rather than the belief that all that awaits us is old age, death, and the grave. Gone forever.