I'm not sure how you've arrived at the point whereby you can claim 'atheists have no clue what the answer is'.
Most atheists are comfortable with big bang hypotheses, because they are science based, they fit with the observable reality of the universe, and more importantly, they are being validated by new discoveries so it appears that the more we find out, the more the universe is confirming for us that these ideas appear to be reasonably cogent.
The rational, logical and scientific answer is that we don’t know.
There are several observable aspects to the universe that are a direct result of it's origin and creation. It's perfectly 'rational, logical, and scientific' to reverse engineer these, hence why science is able to form working hypotheses from them.
If you want to understand why atheists often come across as smug, condescending, or patronising, it's because of the point you mention yourself -
At least religious people (in general) accept that their believe isn’t based on any evidence
So in essence, 'faith' in creator beings, deities and so on, appears no less ridiculous than grown adults believing in fairies, santa claus, or the 'bogeyman' under your bed, and yet people who point out how nonsensical this is are accused of being 'smug'?
Perhaps if people do not want to be ridiculed, they could try not being ridiculous.