I haven't heard this. Atheist don't believe in any religion and that's all. They don't hate nothing. At least the normal atheists. Then there are extremists (as in every kind of this things) that hate something or everything. But this is not to be generalized.
The casual atheist might not hate anything, even religion.
Many people hate things, but it is seldom that they hate things that they haven't thought about a bit... things that they are far more than casual about.
The deeper an atheist goes into thinking about his atheism, the more he makes it a religion for himself. If he thinks about it deeply enough, he will start to get angry at religion, because he can't get away from it. It is right in his atheism. Google "Is atheism a religion?" to see that the symptoms of religion are found in atheism as well as in the formal religions.
People can't get away from religion. A casual atheist isn't atheistic very much.
