My last paragraph was aimed towards religious people and atheists that have a solid opinion.
Alright. Was thinking about this prior to seeing your reply and meant to apologize as on thinking about it your statement could be meant that way and now with the clarification doubt has further been removed. Sorry.
I don't think accepting ignorance is something bad, I advice to do it whenever possible.
I agree that it's not bad to accept legitimate ignorance however I don't think it's best practice to accept ignorance just because it's one of the possibilities. Rather, I feel that ignorance should be the fallback position, over baseless speculation, when hard facts on a subject are insufficient in number and/or scope to paint a reasonably clear picture.
Where sufficient facts on a matter exist to show a clear picture exist I don't believe it proper to accept an assertion of ignorance. Firstly because it's false, we know at least some things on the topic, and secondly because it can be harmful, shysters leveraging 'we don't know' to insert a baseless speculation paired with hawking a product or marketing themselves as a problem solver.
I don't think many Atheists come to the conclusion based off of arguments about the origin of the universe. It appears to be more common that logical or ethical contradictions within theistic doctrine lead to its rejection.
For me personally it began with the divine hiddenness problem. Being raised in a faith that states its god wants a relationship with me and yet is wholly imperceivable to me. From there building with additional arguments such as the abhorrent ethics of their mythical figures when viewed from a frame of reference other than 'they're the good guys because their god said so'.