I think I can sort of understand where this “hates God” thing comes from. For the religious, the existence of their god/gods is as real as their own, and it is unthinkable that he/she/it does not exist. So of course the conclusion is that atheists “hate God” – given the premise that God really exists (and exists independenly of your faith or non-faith), it is a logical conclusion.
But the coin has another side:
If your premises are wrong, it doesn’t matter how stringent your logical derivation is, as the conclusion can never be stronger than your premises. And that’s where they fail; they regard the existence of God as near axiomatic while in reality it is an empirical question if you want to draw any solid conclusions from it. You can play all you want with hypothetical and metaphysical properties and existences, but undeniable empirical evidence is the proof of the pudding.
There is also the possibility that it is a conscious strategy, an attempt to discredit the bothersome “opponents” – atheists – by associating negative attributes with them.