To answer the OP specifically.
What you/creationist view as atheist being a$$holes, is more often than not just "a frustration" from them. The frustration comes from attempting to meet you half way on the subject "usually by discussing fallacy within the holy text/book itself. This is met with disdain because Atheist generally know the holy books better than the professed "religiously devout."
...and religious people will not acknowledge error, hypocrisy, and fallacy....and just cover it all up with a big dose of "Faith."
The second frustration is every religious person argues from ignorance...a huge conversation stopper.
The other thing is many of yall don't understand the different stances of belief and non-belief...here's a couple second video by a damn child that gets it.
Lastly, I do share a concern about how atheist approach a conversation with a religious person. Some are what we call "hard atheist" meaning they basically have no chill. If I was to classify myself it would be in the "soft" category, but since I'm also progressive black...I run into the
"hardest religious" which are religious black people. Specifically AA. Which is flagrantly absurd the more time passes living as an "unpotentialized" people in this day in age.