They also write articles like Jonathan Pierce's article:
Debunking Christianity: Craig, the Kalam, and Quantum Indeterminacy
They cannot accept that the universe (as we know it) is eternal. They are left with trying to show that quantum mechanics allows for material objects to pop into existence out of nothing. Even if we can show that things that "banged" during the "Big Bang" popped into existence due to the rules of Quantum Mechanics, it still leads to more questions than answers. If we ever do figure out the "how?" it tells us nothing about "why?" It does not mean that there is no God. It tells us how God did it.
The thing is that I do disagree with Dr William Lane Craig on a few things. Refuting him doesn't refute God. Craig's critics fail to refute him but that doesn't mean he's right about everything he says. For example. I agree with the video that Craig is wrong about in his philosophical reasoning against infinities, but we don't need that to establish that the universe has beginning.