Here is why I think it might be the case that atheism and hate of Islam has correlation:
Islamic God is the only God with proof.
Atheists want to only believe on truth and proof.
They find a God that just watches (Deism) irrational.
At the same find other religions irrational.
While a Deist or Neopagan or Soothsayer, or whatever religion with no proof, they can convince themselves of God without evidence to what the true God is and be averse to the Islamic God, the nature of atheists is they only want to follow a proven and reasonable God. To me that is Islam, but what keeps them from it, is the hate they have for how Islamic God has been portrayed by Muslims.
So the one religion which has proof, though, they are averse to see the proofs for God and the truth with respect to religion it has, because, they don't like the Islamic God.
I don't fully blame them, because Muslims have done a bad job in displaying the proper justice God commands to and have ascribed a very warped and bad morality in terms of religion to God.
But this thread is to discuss all this and deal with reality and perhaps a solution.
So while they wouldn't mind a Deistic or Soothsayer Wiccan type God, they know those are irrational and lack proof.
The more reasonable one and the one with proof however is hated and so they are averse to God all together for that reason (my perspective).