Your answer to my quoted question is as much a non-answer as turtles all the way down. "Don't worry your pretty head about it" is no answer either. It is, however, the typical last resort of the religious. It is not an acceptable answer, and teaching that response isn't acceptable either. The contradiction is not simple and is not resolved just by saying it's not there.
In any case, I was not aware that Big Bang is being taught in primary school. I have no recollection of it being taught when I was in school. "Science Class" as it was called before we got into high school and started being taught classes with titles like Chemistry and Physics and Biology, was far more concerned with teaching us things like bird recognition and the anatomy of algae. I recall no discussion at all about the origins of the universe, or even anything about cosmology in general. I guess times have changed. I'm going to take your word for the change in curriculum.
Taking you at your word, then I have a problem with the current curriculum as well. Big Bang should not be taught in primary school. It wasn't, when I was in school, and it should be removed if it has crept in. Cosmology suffers from the same fault as climatology and geology: all three are purely observational sciences. Calling them science is a bit of a stretch in consequence. They're half sciences. Exacting observation is very much essential in science, but it is only half of the process. The other half is experiment, followed by further exacting observation. Observation without experiment, and in particular multiple parallel experiments with controls, is perhaps useful, but if it's science, it's a much weaker kind.
Worse, all three subjects have, to all appearances, existed for vastly long timescales, and our period of exacting observation is only a tiny tiny fraction of that time. Conclusions about very long lasting processes using very short observational periods are often shaky, statistically. We're finding out just how shaky only recently, as we start seeing the assessments of scientific papers in many fields by statisticians, and learn just how poor the math really is. Even those observing short processes are poor. Slashdot has covered that particular revelation recently, and I think the implications and revisions are going to ring throughout science for a couple of generations, at least.
If anybody is still reading this far in the past and this deep in the thread, I'll get dinged for distinguishing between experimental and observational science and giving observational the short end of the stick, but my karma can take it.
To address your dilemma, it is not acceptable to teach anybody's fairy tales with taxpayer money. If the separation of church and state is about nothing else in this day and age, it is about the distribution of money. (Since apparently every damn thing is about the distribution of money.) Government that promotes dogma is the greatest scourge the Earth has ever seen, and I include not merely the de facto church government of Catholicism during the Middle Ages, but the Stalinism of the modern age as well. Both were horrific, and for the same reasons. Stalinism behaved like any other religion, despite its nominal atheism. You could classify it as a non-deistic religion, if that makes you happy.
More to the point, the particular fairy tale you seem to be interested in is not an appropriate subject for taxpayer funded classrooms for another reason: it is invariably not about the question and the philosophy, but about a very specific answer, namely, Christianity. Clothing the subject in terms of the question and the philosophy is always, in America, a Trojan Horse, and that metaphor is particularly apropos because it is, in every respect, an assault by an invading force that will wreak havoc once within the walls. That is the reason for the serious pushback against even bringing up the question in the modern public classroom. The question is a false front, and the people asking it aren't even remotely interested in high minded debate, or philosophy, or critical thinking, or logic. They are only interested in asking the question as an excuse to give their pet answer: God with a capital G. God who killed himself to appease his own wrath. And all that rot. I've never heard of Larry Kraus, but his tag line is quite accurate, and I hope he is making assloads of money. But I very much doubt he's making any of that money from public funds.
My opinion of the question is relevant to anybody who is honestly interested in the question, and not some specific answer they think they already know. You betray your own biases right there, by dismissing my opinion while claiming, in the very same paragraph, to be interested in opinion. You're not. You're part of the problem. Countless people do indeed find the question entertaining and challenging and important. Me, I think it's mental masturbation. It's the wrong question. And that's why we shouldn't be bothering children with it. They're not being denied the chance to learn. They can sit around in coffee houses and wank as philosophy students as much as they like. In college. Or in bars. (If you can distinguish the two.) Even in church, if a church would go so far as to discuss alternatives to their pet answer. (None of the ones I've been to ever did.) It's a ridiculous subject for primary school, and should be kept out in any form.
Primary school is for teaching the things we KNOW. 2+2=4, always. The Earth is an oblate spheroid. "I" is the subject form of a personal pronoun and "me" is the object form of the same personal pronoun. Shakespeare wrote a lot of plays. Water is made of hydrogen and oxygen. And by the time we exhaust the list of things we KNOW, there's no time left for philosophy, and I'm fine with that. It can wait. Pattern their brains with truth, as tools for dealing with the world. Leave the guesswork for later.
If the curriculum needs to be adjusted, it's to remove Big Bang, not introduce America's majority fairy tale as an alternative. Allowing that giant wooden horse within the walls is a very dumb idea.