In UK atheists considred more moral than theists.

[Aroura]

Not to be pedantic but that is not the definition of omniscient. You can try and suggested all knowing means he must therefore make perfect decisions but I would disagree that it necessarily follows.

To be considered pedantic you'd have to be right...

Go ahead and explain in the scenario in which someone who knows every outcome of every decision would make a mistake.

That isn't what pedantic means, either.  A person can be nitpicky and still be incorrect.  Just as a being can know everything and still be a dick. Also, that being is not, by definition, also able to do everything, so they might not be able to take the action they deem "perfect".

So if a being knew every outcome but could not take all actions, that's a perfect example of your requested scenario.  Or if they knew every outcome but desired a negative outcome, that's another example of your requested scenario. 

Now if you pair omniscient with omnibenevolent and omnipotent, you might begin to have an argument, but then we butt up against the problem of evil.

But yeah, you can't just toss out one of the three and act like it covers the whole gamut.  It doesn't.